Ortofon ST-70 Moving Coil Transformer Review

[Sokel]

I get it, but suggesting a tool for a use case it wasn't intended for without disclosing said limitations or how to navigate them doesn't set someone up for success.

I get it too, that's why I asked him to share some samples.
It would be easy for anyone to test them.

Mine was just an example.

 

[Sokel]

No, go on the second tab showing all curves and do trace arithmetic as I wrote

That's what I did, I do it all the time.
The results of A over B and A magn over B magn are the blue ones.

(that's the second tab you see there, just enormously minimized to fit both waveforms and trace arithmetic results)

 

[Balle Clorin]

To much sunlight on my iPhone can’t see any blue curve..but now I see it, does look like the difference ?

 

[AaronJ]

Is it possible to explain in layman’s terms what you are investigating? I don’t have the technical knowledge to understand but I am interested and trying to follow. Very much appreciated.

 

[Bob from Florida]

DeltaWave doesn’t work well with vinyl due to the speed irregularities.

What speed irregularities do you mean?

 

[morillon]

What speed irregularities do you mean?

w & f.... (?)
;-)

 

[Balle Clorin]

Like that?
(That's peaks only of course)
Red is flac, Green is LP.

View attachment 463001

I first aligned SPL at 400Hz which the previous showed small tinny difference and for 5 octaves as the general level difference between the two is big and applied 1/3 smoothing.
Let me know if you want some other view, haven;t closed it yet.

Edit: added magn,

You are doing somethin strange difference is not 50db… , do not use peak, and import the same length track. Make sure both track are at same level( correct in REW).
Here is two music tracks compared with two different cartridges.

Here is the difference method used on Xindak MC-10 (26db), track is frequency sweep. Load 47k , ca 200pF. Cartridge internal resistance 12 ohm.

Not a very good match with the cartridge by the way, -1db at 40hz and pleaking before 20khz
Sony HA T10 =Ortofon T5 is a much better match for this cartridge, internal resistance 10 ohm, same load as above

https://www.vinylengine.com/library/sony/ha-t10.shtml

Spoiler: off topic

while we are at it,,, the difference method used on two different turntables--, Clearly difference in arm resonance and vibrations

 

[Sokel]

You are doing somethin strange difference is not 50db… ,

You're reading it wrong, the difference you see is relative to the levels of the tracks of the song.
It's easy to confuse as we get used to see the tested FR as a straight line, but this is a song tested, not a sweep or white periodic noise.

 

[Soniclife]

You are doing somethin strange difference is not 50db… , do not use peak, and import the same length track. Make sure both track are at same level( correct in REW).
Here is two music tracks compared with two different cartridges.

Here is the difference method used on Xindak MC-10 (26db), track is frequency sweep. Load 47k , ca 200pF. Cartridge internal resistance 12 ohm.

Not a very good match with the cartridge by the way, -1db at 40hz and pleaking before 20khz
Sony HA T10 =Ortofon T5 is a much better match for this cartridge, internal resistance 10 ohm, same load as above

https://www.vinylengine.com/library/sony/ha-t10.shtml

Spoiler: off topic

while we are at it,,, the difference method used on two different turntables--, Clearly difference in arm resonance and vibrations

View attachment 463049

OT slightly, do you have 2M Bronze measurements?

 

[Balle Clorin]

@Sokel

Spoiler: For Sokel

Hmm , I think we misunderstand each other’s objective. Type of track is irrelevant, mine tracks are both music and pink noise and sweeps, all can be used for a difference track, I adjust the levels to see the relative difference, = deviation from 0.

Take a a look at your plot at 20hz one curve has a value of 79 and the other 82db, the difference is 3db, not 30db as you blue curve shows.

 

[Balle Clorin]

OT slightly, do you have 2M Bronze measurements?

Not a sweep, only difference vs OM30

 

[Sokel]

@Sokel

Spoiler: For Sokel

Hmm , I think we misunderstand each other’s objective. Type of track is irrelevant, mine tracks are both music and pink noise and sweeps, all can be used for a difference track, I adjust the levels to see the relative difference, = deviation from 0.

Take a a look at your plot at 20hz one curve has a value of 79 and the other 82db, the difference is 3db, not 30db as you blue curve shows.

Oh, I see what you mean now, my bad as I should have deselected max gain since I SPL aligned them.
That's the proper one:



Thanks for the reality check!

 

[Sokel]

Is it possible to explain in layman’s terms what you are investigating? I don’t have the technical knowledge to understand but I am interested and trying to follow. Very much appreciated.

It's a silly exercise about whether we can compare digitized vinyl samples (or dig, vinyl vs flac, etc, songs at this example) .
@JP is right about been better tools out there, we just want to see if we can get good hints using the popular (free) ones.

 

[Bob from Florida]

w & f.... (?)
;-)

If @JP , means w&f - would that be a problem with the Technics SL1300G?

 

[Mnyb]

If @JP , means w&f - would that be a problem with the Technics SL1300G?

For file comparison it would be a problem with any TT combination or even the same TT , the randomness of Wow and Flutter and other speed variations practically assures that no playback is ever the same .
may not be audible , but the software will definitely pick it up .

 

[Mnyb]

For file comparison it would be a problem with any TT combination or even the same TT , the randomness of Wow and Flutter and other speed variations practically assures that no playback is ever the same .
may not be audible , but the software will definitely pick it up .

.. for example if the whole song is 0.1 s shorter or longer due to time of the day with an TT with a synchronous motor due to grid frequency variations . This will thrash the whole compare process , the files will not align .

I suppose some software have tools to normalize the pitch etc but it's still hit and miss compared to the predicable repeatability of digital ? Such adjustment may twart the test in other ways i assume

 

[Bob from Florida]

.. for example if the whole song is 0.1 s shorter or longer due to time of the day with an TT with a synchronous motor due to grid frequency variations . This will thrash the whole compare process , the files will not align .

I suppose some software have tools to normalize the pitch etc but it's still hit and miss compared to the predicable repeatability of digital ? Such adjustment may twart the test in other ways i assume

The Technics is accurate with speed and w&f is < .025%.

 

[Mnyb]

The Technics is accurate with speed and w&f is < .025%.

Seems like a good number , but I'm not knowledgeable enough to asses exactly what this mean for our comparisons but still random variations even small ones will limit us .

Some online calculator equals 0.25 with -36.02dB There is probably a finer point i miss here maybe its not that simple with w&f as in distortion ?

Also you can have slow speed variations even with quartz controlled decks for example if you had two of these very nice technics i'll bet they don't have the exact same rotation speed on average no TT will go exactly 33 rpm or 45 rpm even if the w&f number is 0.025% around the average speed .

Suppose direct drive is much better than belt or idler wheels where the status of belts and idler wheels makes a difference and the mfg tolerances of motor wheels and platter .

 

[Bob from Florida]

Seems like a good number , but I'm not knowledgeable enough to asses exactly what this mean for our comparisons but still random variations even small ones will limit us .

Some online calculator equals 0.25 with -36.02dB There is probably a finer point i miss here maybe its not that simple with w&f as in distortion ?

Also you can have slow speed variations even with quartz controlled decks for example if you had two of these very nice technics i'll bet they don't have the exact same rotation speed on average no TT will go exactly 33 rpm or 45 rpm even if the w&f number is 0.025% around the average speed .

Suppose direct drive is much better than belt or idler wheels where the status of belts and idler wheels makes a difference and the mfg tolerances of motor wheels and platter .

Measuring speed with the Parks Audio Waxwing Phono preamp shows absolute speed accuracy every time. It does this by measuring the 1 click per rotation on the runout track. With different weight clamps- 8 ounces to 32 ounces - it still measures exactly on speed. My belt drive table would measure different speeds every time I measured it, so I don’t think speed accuracy is going to be an issue on playback. Now, if the recording lathe had a speed issue, then that is “baked” into the album.

 

[Balle Clorin]

.. for example if the whole song is 0.1 s shorter or longer due to time of the day with an TT with a synchronous motor due to grid frequency variations . This will thrash the whole compare process , the files will not align .

I suppose some software have tools to normalize the pitch etc but it's still hit and miss compared to the predicable repeatability of digital ? Such adjustment may twart the test in other ways i assume

I theory yes it is a problem, but in reality not a big issue. See post #247. Here is showing a high pass filter effect of some kind, above the filter the file frequency response is 100% the same