Fun with vinyl measurements

[USER]

Are these result from a different test record? Test records may differ depending on pressing and master. They should be numbered/dated for reference, IMO.

The measurements is from mackat. He provided me nearly 30, all made with the same test record as far as I know. This is the one anomaly. More, I have never seen this phenomenon before from any CBS STR-100 measurement.

 

[Thomas_A]

The measurements is from mackat. He provided me nearly 30, all made with the same test record as far as I know. This is the one anomaly. More, I have never seen this phenomenon before from any CBS STR-100 measurement.

From description of MC-5, below. Don't know if warped test records and/or the suspension construction has anything to do with this, but if suspension is non-linear in any direction, it may affect crosstalk. I think. Keeping the stylus "steady" in warps should improve crosstalk.

"Newly developed Equalizing Damper is used for the damper part.
This damper has a structure in which a step is consciously provided on the surface that contacts the upper part of the armature in the V direction. When a needle pressure (1.2g) is actually applied, the cantilever is controlled so that the center of gravity of the vibration system is on the straight line connecting the tension end and the vibration supporting point. This clarifies the vibration system operation, and by using this step, the compliance in the V direction is appropriately controlled, and adverse effects such as warping of records are suppressed.
In addition, the newly developed damper is stepped to vary the thickness and shape. This satisfies both the condition of widening the contact area required for low-frequency reproduction and the condition of making the contact area small and thin for high-frequency reproduction, and realizes uniform spectral balance over all frequencies."

 

[Thomas_A]

An addition; dampers or higher arm-cartridge resonance that makes the stylus move less in warps (i.e. LF signals) should in theory give better cross-talk. Everything that lets the stylus be centered in the armature during play would improve crosstalk, allowing the stylus only to move purely +/-45° in left/right directions for audio signals.

 

[USER]

So I guess the question is if those crosstalk measurements are repeatable on another CBS record with that cartridge. And if so, what does that mean with respect to the latter. Do they all have the potential for better crosstalk measurements? If so, does that translate to other test records?

@mackat: do you have any additional info regarding your MC-5 set-up and the CBS test record(s) you use? (See last few responses.) This is a rather interesting result.

 

[JP]

I’ve an NOS MC-5. Will add it to the list - winter is close.

 

[ivanj]

Are these result from a different test record? Test records may differ depending on pressing and master. They should be numbered/dated for reference, IMO.

Questions for inquiry:

1. Does your room or cartridge temperature change? I recall that Lyra likes their cartridges to be in a 'warm' environment. Something to do with suspension 'rubber ' damper.

2. Cartridge age and dampers. Most of these cartridges are 'venerable.' Consider card suspension/tires? As far as I recall , the cartridges OPs mention are fairly old, for example, the Technics EPC-270cCii or Yamaha MC-5 even if they are NOS. Might have something to do with their rubber suspensions/dampers 'drying out'? Consider speaker surrounds they decrepitate with age.

3. Original specs - most of them are 25-28dB of separation. You're lucky to be still getting it with older cartridges. Maybe it is not the test records fault.

4. Does anyone have a 'new this year' cartridge to test?

 

[Thomas_A]

The cart/arm is "free to move" along the warp and record off-center, and even if you have the resonance frequency at 10 Hz, you will get some stylus movement. This dancing gives a fuzziness to the audio signal. A movie below to originally show the side-movement of too high anti-skate force, where the cartridge body moves to the left relative the stylus, but i also shows some of the dancing behaviour. Watch 30 s at the end of the movie.

Hmm .mov not compatible here...

now:

M20180628_004.mov

Shared with Dropbox

www.dropbox.com

 

[USER]

Questions for inquiry:

1. Does your room or cartridge temperature change? I recall that Lyra likes their cartridges to be in a 'warm' environment. Something to do with suspension 'rubber ' damper.

2. Cartridge age and dampers. Most of these cartridges are 'venerable.' Consider card suspension/tires? As far as I recall , the cartridges OPs mention are fairly old, for example, the Technics EPC-270cCii or Yamaha MC-5 even if they are NOS. Might have something to do with their rubber suspensions/dampers 'drying out'? Consider speaker surrounds they decrepitate with age.

3. Original specs - most of them are 25-28dB of separation. You're lucky to be still getting it with older cartridges. Maybe it is not the test records fault.

4. Does anyone have a 'new this year' cartridge to test?

Thanks for the questions. As best as I can tell this is what I think.

1. Have to ask @mackat if there was something different with the measurement set-up. As far as mine go, as I wrote on the intro all my measurements are taken in temperature between 68-72 degrees F year round. But I have had consistent results in terms of crosstalk, never anything like the one outlier posted.

2. I don't understand how a dried out damper would result in both superlative crosstalk measurements for the Yamaha and the test record working better. At this point I think there is a lot of evidence in the FR that says if there is a suspension or damper issue. I'll post damper restoration measurements in the near future, though if you are interested now old versions of those measurements have been posted here somewhere.

3. Perhaps. And that often depends on how they were stored. But plenty of the ones posted here perform to spec. Certainly there are those Technics that fail, the Shure VN45MR stylus, and some A-T dampers that dry out but these are surprisingly very robust little things. I think the failure prone ones are become better known and reasons better understood. Also note that it is becoming more clear that many cartridges are underspec'ed because manufacturers were using the same test records we were at times. My Shure V15 V-MR measures at -35 dB crosstalk at 1kHz on a DIN 45 435 test record. Spec is -25+ dB. I get -30 dB on CA-TRS-1007.

4. Do you know what some of the new cartridges are? I have no idea what has come out this year. Perhaps Audio-Technica updates? If so there is likely information available regarding them.

 

[mackat]

So I guess the question is if those crosstalk measurements are repeatable on another CBS record with that cartridge. And if so, what does that mean with respect to the latter. Do they all have the potential for better crosstalk measurements? If so, does that translate to other test records?

@mackat: do you have any additional info regarding your MC-5 set-up and the CBS test record(s) you use? (See last few responses.) This is a rather interesting result.

There wasn’t anything interesting that I can remember. It’s the same setup I used for the DL-303 measurement as well. The only things that I believe could have been different were headshell, potential azimuth, and VTA differences.

Technics SP-15 > EPA-250 > Sutherland KC Vibe preamp > quality RCA switch box > Focusrite 2i2 > Audacity

 

[aaaakkkk]

Perhaps the diamond is mounted on the cantilever at a different SRA angle, which is why I suggested conducting an experiment with the cartridge tilted +-5 degrees.

 

[Balle Clorin]

The Gyro is feeling good today…B&K QR2010 test record
The NAK T-100 is a useful tool, easy to see the effect of adjustments. Test Record centering etc.

Here is the log file plotted

 

[Balle Clorin]

Not sure how to include the sound when looping the PC recording output-input. Instead you hear the washing machine…

Centring by trial and error.

 

[Thomas_A]

I'll see if I can test my QR2010 copy tomorrow after USB microscope alignment. It's not the best condition of my record though, it would need a really good clean.

 

[Balle Clorin]

Just to have a backup I got a second CA-TRS-1007 frequency sweep test record. I read they are hard to get now, but a local Clearaudio dealer imported one to me.

 

[Balle Clorin]

I think I see some erosion spots above here!!

Got an old Denon DF-21F (1983-85?.)
It is for spare parts since it works and have the same motor and arm microprocessor as my 51F . With it I got the Ortofon OM 5E too. Just a matter of getting a NOS OM30 then…

WF WRMS twice of spec,, the positional photoresistors are also troublesome, does not stop when returning to armrest.

Polar plot

Not as good as the 51F

 

[stereoplay]

I got a DP-21F once before. It measured horrible.
Can you show your results of W+F?

 

[Balle Clorin]

Not as good as spec 0.03 WRMS

I got a DP-21F once before. It measured horrible.
Can you show your results of W+F?

Edited in above..

 

[USER]

Not as good as spec 0.03 WRMS

Edited in above..

That one needs motor cleaning. May make a good practice turntable if you got it cheap.

 

[Balle Clorin]

30USD,,, maybe an object I can train on doing Capacitor replacement, and the Photoresistors are clearly not working well, buttons do not always work and TT now does only occasionally shut off motor when STOP. Worked fine when I picked it up , but the seller warned be about inconsistent behavior.

 

[USER]

30USD,,, maybe an object I can train on doing Capacitor replacement, and the Photoresistors are clearly not working well, buttons do not always work and TT now does only occasionally shut off motor when STOP. Worked fine when I picked it up , but the seller warned be about inconsistent behavior.

One of these makes desoldering capacitors easy. Just make sure to let it fully warm up.

Amazon.com