For W&F measurement, the very first thing is that you need tools. A phone is a useless device as it causes extreme imbalance, which can’t be tolerated while measurement. First, you need a record that has 3000 or 3150Hz on it prerecorded. Example DIN 45 545 where both sides on the full-length is dedicated for this measurement, with this I could achieve the best measurement (the outer track has a 0.01% adder, while the inner 2-3records is better as I observed). Also nice, my favorite vinyl Tacet, which can also help in many other measurements and is top to set antiskating ( has ~0.02% “built” in Wow!). Also good, the very well (over)engineered test record from Hungary (this has also some wow adder, but likely as it is on the outer edge, like the Beuth).

Above of the record, you need something to evaluate the tone. Hardware solution EMT 424 is nice, but hard to keep such old machine alive and calibrate it, while results are very limited compared to software solutions. Such software could be the WFGui, which can measure W&F, but is really bad when it comes to the question, why is it that bad?

I personally like the Nakamichi T100 inspired NAK-T100 . Made a video, which we can analyze and learn about possible steps while reading data measured with an Elac 22H turntable.:

On the above picture nothing much interesting. You need to select 3150Hz, which then matches with what is on the recording. You finetune the speed of the turntable mechanically or by setting the motor frequency with turntable power. The deviation meter will be in the middle of NAK T-100. The bottom graph shows the deviation in time and draws it continuously. The aim is to get this as flat as possible. But how? Here, the second instrument helps in understanding:

As visible, 0.121% is the weighted RMS W&F. The 2 type of contributors are:

-Wow, that is a slow rotation speed change of the turntable. Like how cat says “meow”. Such slow changes are caused by the plate imbalance (33 1/3 is ~0.5Hz ) or by slow motor speed changes < 0.5Hz, by belt weakness…

-Flutter is a fast change. This is more annoying in the tone. The sample video above demonstrates this clearly, a fast vobling tone on the 3150Hz. The source of such is typically the drivetrain as its moving parts are rapidly enough to cause such(wheel, idler, motor ). But we may also think on a tonarm resonance on 10Hz induced by self resonance (good to measure and know tonearm resonances!).

Good idea to change measurement method to Quasi-Peak, which is more sensitive for Flutter. Increasing sensitivity 0.5%–>0.1% helps to better visualize the spectrum, where we would see 3 peaks:

-0.5Hz, ~2Hz, ~10Hz

Measuring through the wheels, knowing the turntable plate RPM(33 1/3), we can calculate all RPM’s or the frequencies of the drivetrain parts. Here harmonics (double) are also interesting to watch for.

Now it is obvious! 0.5Hz is caused by the plate imbalances. The ~10Hz turned out to be caused by incorrect Idler height, where it was touching the next (45RPM) speed wheel just slightly and causing a flutter close to 10Hz. This frequency made the Idler as suspect. Was 8Hz when zooming in. Likely was touching the motor wheel twice/every turn if you see the relation of ~3.4Hz what I calculated for the Idler.

So, analyzing the spectrum, comparing to drivetrain frequencies can help to identify the reason for the bad result!

As a result of fixing the mentioned Idler height, here is the good measurement. Of course, I was cheating, with lowering the voltage, as running on 230V causes way more motor rumble, which then lowers W&F with ~0.02%. To cheat more, decided to run the motor on ~37Hz while setting the drivetrain to 45RPM mode. The W&F in this setting dropped further to 0.05%. As visible, the plate wow remained. Now purchased Mitutoyo clock measures to analyze how I can make this better.

I expect that while improving, it will be hard to tell if W&F or it is rumble what we measure. So I also sourced  DIN 45 544 vinyl, and may(500EUR!) to source a measure adapter, which is a different way to measure rumble(while more sensitive to not measure groove noise, it is seeing vibrations that the vinyl is filtering out).

The current Elac 22H result is 0.035%!, with the audiovault Idler. This is very close to the DD results, where it is interesting that WRMS is shared in spec , to hide flutter, which I think is a likely DD problem.

Audiovault helped me with fingerpointing on the oil variations (viscosity, ISO48, ISO68). Is critical, that the sintering bearing gap is well filled up, so axis is super stable. I used ISO68 on all Elac bearings.

Beyond all the above: With all records ~0.01-0.02% of wow (0.5Hz) can be added due to the wrong positioning of the hole. Unfortunately, the mastering vinyl loses its hole and a new one is punched while vinyl manufacturing, which is not always exact to the groove’s center. With the centering tool (385EUR) you can make measurements repeatable, but if the punching is bad, you have that bad constantly. Due to price, I am making my own interpretation here. Best solution is DSAudio ES-001, which detects the inner groove fluctuation, but hey!!! 5kEUR for 0.01% Wow? Actually, they lie when they claim flutter, as this tool reduces only the 0.5Hz range wow, nothing else, but that works really well.