Fun with vinyl measurements

[Thomas_A]

Well, tough crowd, I suppose... With all due respect - this graph looks like math, not actual measurement? I'll read the paper when I have extra time, but for now color me skeptical.

Yosh graph is calculated for 5 cm/s (not 10 cm/s), so distortion drops to 0.2-0.3% in the middle bump. Korf had a Baerwald calculation probably at 10 cm/s peaking at 0.6-0.7% for the middle bump. If testing is done on a "-10 dBu" record, what does it mean in cm/s? dBu is relative to 0.775V so I have no idea what it means.

 

[Thomas_A]

Still Korf shows how superior advanced styli are, and why no serious audiophile should use a conical stylus..

Josh reasonings and sources are probably based on conical and ellipticals ?

Yes, Yosh has more or less simulation using "balls" and spherical stylii. That tracing distortion dominates and increases at end of record (as Korf showed) for conicals and ellipticals is nothing strange. It is just that a comparison with the replicant stylus and theoretical distortion needs to be done using the same velocity. Is the 1 kHz signal recorded at 10 cm/s?

 

[Palmer]

Yosh graph is calculated for 5 cm/s (not 10 cm/s), so distortion drops to 0.2-0.3% in the middle bump. Korf had a Baerwald calculation probably at 10 cm/s peaking at 0.6-0.7% for the middle bump. If testing is done on a "-10 dBu" record, what does it mean in cm/s? dBu is relative to 0.775V so I have no idea what it means.

Well, I have reached out to Korf Audio to run that by them, but that is my point - Yosh does calculations, which is perfectly fine of course, but it would be interesting in actual measurement results - hence Korf has the Baerwald calculation on the graph, together with the actual measurement off the test record to compare, methinks. Worth the effort, should be a rewarding endeavor going forward.

 

[Thomas_A]

Well, I have reached out to Korf Audio to run that by them, but that is my point - Yosh does calculations, which is perfectly fine of course, but it would be interesting in actual measurement results - hence Korf has the Baerwald calculation on the graph, together with the actual measurement off the test record to compare, methinks. Worth the effort, should be a rewarding endeavor going forward.

Sure, measurements are always interesting - and valuable tools to both understand and use them for set-up. But there is a need also for correct information regarding the conditions - in this case, the level of the 1 kHz signal.

E.g. the 1 kHz L+R signal of the CA-TRS1007 is recorded at 3.54 cm/s RMS and 5 cm/s peak, and I get distortion numbers in the range of -60 dB (0.1%). The L+R track is placed ≈115 mm, close to the null point.

Post in thread 'Parks Audio Waxwing measurements'

Aug 18, 2024

I'm still waiting for someone to measure the SINAD of actual vinyl playback.

Around -70 dBA as best? THD+N below seems wrong though; THD at -62 dB and Noise at -55 dB.

• Thomas_A

• 

 

[JP]

Well, I have reached out to Korf Audio to run that by them, but that is my point - Yosh does calculations, which is perfectly fine of course, but it would be interesting in actual measurement results - hence Korf has the Baerwald calculation on the graph, together with the actual measurement off the test record to compare, methinks. Worth the effort, should be a rewarding endeavor going forward.

Extraneous contributors cannot be removed from such measurements, which makes them practically worthless in a narrower context.

 

[Balle Clorin]

Not Bering English , I almost had to ask, but I see what you mean. Too much disturbance from other things

 

[Palmer]

Extraneous contributors cannot be removed from such measurements, which makes them practically worthless in a narrower context.

Nothing is ever really worthless, in my experience, and I have not yet achieved to walk into a narrow context. We shall see.

 

[JP]

That’s just silly.

 

[Balle Clorin]

Hana ML measurements
Put it here to not pollute the measurements library. Notice the high output and Ortofon like response

https://youtek.jp/img/topics_202008_01/STEREOPLAY_Testbericht_Hana%20ML.pdf

 

[Balle Clorin]

Now THIS is FUN, my JVC TRS-1007 arrived today- with original plastic wrapping and all. Perfectly flat too…

 

[Thomas_A]

Lucky you!

 

[Balle Clorin]

yes, pure luck..a random scrolling on discogs and it turned up, could not believe my eyes and with shaking hands I snapped it.. I never got any Discogs alert even if it was on my watchlist.. strange.

 

[Balle Clorin]

Just an example on how important leveling is… the results are repeatable..
Fisher MT-6330.. (suspended internal chassis )the adjustment difference is slightly less than 1mm on one fot.
Ymmv

 

[narud]

After picking up the Audio Technica ML170, I decided to re-install the damper on my technics sl1700mk2. I have an album that lays relatively flat, but has lots of tight, wavy warps on the edge that really excite resonance on carts. I was curious to see how much of an effect the damping would have on reducing the amplitude of the resonant peak. Here's what it it ended up looking like.

It was interesting seeing a measured effect of using the damper. I used to keep it installed when I was using an at33ptg2 as my main cart. I never looked at a before and after though.

 

[Balle Clorin]

I put together an external DC regulated power supply to feed to my experment turntable Fisher MT6330..

In principle what I did was this. But with another not so crappy and dangerous SMPS, and I added a LM317 regulator unit.
By coincident the regulator display show the V-DC value both with AC feed and DC feed..

The Voltage does not affect rpm... and wow and flutter is also the same with AC and DC supply

DC removes 200Hc noise component, but does not affect 67hz rumble/cogging , nor 100Hz peak. the 100Hz peak may be part of my measuring setup, always present..

Or maybe the 200hz peak is hidden by the riaa noise floor, have to redo run with RIaa

200hz DISTURBANCE WITH AC POWER CONFRMED

67Hz cogging and 100Hz peak shows up as sidebands but 200Hz do not, 200Hz must be electrical

 

[Balle Clorin]

@Thomas_A , you asked about clamping effects. The Michelll clamp must be used with the felt pad. Both clamp, weight and alternative mat can improve things.
In my fisher MT-6330 I get best results with SRM-Tech mat combined with Michell push clamp using the included felt pad under the record.. skipping the felt pad gives a bum at 12-15hz

FORGOT TO INCLUDE WEIGHT CLAMP VS MICHELL PUSH DOWN...

 

[Thomas_A]

@Thomas_A , you asked about clamping effects. The Michelll clamp must be used with the felt pad. Both clamp, weight and alternative mat can improve things.
In my fisher MT-6330 I get best results with SRM-Tech mat combined with Michell push clamp using the included felt pad under the record.. skipping the felt pad gives a bum at 12-15hz

View attachment 476169

View attachment 476170


FORGOT TO INCLUDE WEIGHT CLAMP VS MICHELL PUSH DOWN...

View attachment 476171

Thanks. This is with no sound waves (silent room)? I was however specifically wondering if there is any difference with or without clamp (with felt pad) while running high SPL pink noise or 20-1000 Hz sweep through the speakers. The player could either have a stationary stylus or as in real life running in a silent groove or a 3150 Hz groove while the sweep or pink noise is playing.

 

[Balle Clorin]

Music room not available today, no feedback tests
just som sweeps..with mats and clamps, not much effect on reponse, that is why i posred ther low ende where there is a difference

SRM mat+clamp

SRM MAT+ WEIGHT

ORIGINAL MAT NO CLAMP OR WEIGHT

 

[alvaro-oliver]

I don’t know what differs at the moment; I have to dig more in the weekend. Same file same software should give the same result Unless there is some settings that differ. Perhaps also @alvaro-oliver can chime in on the difference re noise. 2sigma of 0.3268 vs. 0.113 for the noisy Denon track seems too large. What is the general accepted method for 2-sigma? Virtins?

Hi Thomas, sorry for the delay in replying—I hadn’t had a chance to check the forum.

Thank you very much for sharing your results. There’s definitely something wrong with the frequency counter in my script, which is becoming evident with the Denon disc recording.

As @Balle Clorin pointed out, the script calculates frequency using the zero-crossing method, which is the one recommended by Virtins. However, I’ll review the filtering chain using your file, as it’s possible that noise is affecting the measurement—just as you and Balle have already suspected.

As soon as I have some time, I’ll revisit the implementation and share an update.

Best regards!

 

[Balle Clorin]

The frequency can be found by other methods, I cannot recall exactly but AI/coplitot has written some Python scripts for me - calculating wow and flutter and so on… it may give you suggestions too.
Zero crossing would need heavy filtering to remove low frequency garbage and clicks and pops filtering that affect the zero crossing