3 New UBER Decks - Is this Turntable's SwanSong? 🦢

BTW the TT-101 is one of the TT's that has the subsonic resonance.

Please have the courtesy to show the evidence for this statement...🤥

Dear @halcro : Years ago when every one including you were touted the JVC 101 I posted at least 3 times in those threads ( in your thread. ) that the 101 was an average TT with nothing especial to say Wow.

I know that you was so angry with me because my posts about but its specs are really mediocre/average for a DD unit with a w&f 0.02% and s/n 75db, normal for average TTs. Denons way superior on specs and some of its models came with bi-directional servos too but Denon decided not a good thing and return to single servo including in its top DP-100.

Other that what Richard pointed out a fact is in the price that had the 101 that was low:

The top of the line 801 specs were similar to the average Denon’s: 0.01% and 80db. This unit came with hold down LP mechanism and even that characteristic its price in Japan was 130,000 Yens when the Technics MK3 was ( in the same year. ) 250,000 Yens ( MK2: 150K. ). The 101 was 75K. These data comes from the audio Japan Bible.

Is it a bad TT ? no but you overrated with no clear facts that even today you have not and that’s why you are questioning RK.

Don’t distress about because you are enjoying it and this is what matters to you. So what ! ! the TT still is an average unit and nothing more.

Btw, even with out the RK posts all what I posted here is the same I posted years ago and I just confirmed again. Nothing changed and og course is only an opinion.

R.

Halcro.

I think that the numbers and green graph are useful provided their limitations are taken into account.

Mean frequency....

This is a good number to have. We are looking for 3150Hz, so nice and close to this is desirable.

Raw frequency…

Max deviation. (relative ) This is the max percentage deviation, negative and positive, from the mean frequency. Ideally the two numbers should be the same

Max deviation (absolute) This is the max frequency deviation, negative and positive from the mean frequency. Ideally the two numbers should be the same.

What the deviation numbers do not show is the variation between the deviation of individual positive and negative swings. They all should be the same, (constant amplitude) and for this information we need to refer to the yellow graph.

Lowpass-filtered Frequency.....

This data taken from the green trace. The limitation here is that this trace is heavily filtered version of the yellow trace. And it is very inconsistent from test to test.

Look at the 1000R yellow trace and compare this with the TT-101 yellow trace. There is an enormous difference yet, post filtering they yield very similar green traces  

I have run sequential tests on my SP10 Mk 3 and got Low pass -0.01%/+0.01% followed by -0.02%/ +0.03%. I have outlined some of the reasons for this inconsistency. As I said earlier, below a certain percentage, these figures aren't robust.

Obviously we do not want to see any standout perturbations in the green trace and in this way it can be very useful.

My point is that this data is derived from the yellow trace which is taken from the cartridge output. After all, it is the cartridge’s output that we listen to. To really see how the TT is behaving in fine detail, we need to analyse the yellow trace from the perspective of what a perfectly speed stable TT would look like. A clean sine wave, symmetrically centred around 3150hz with a constant amplitude for each cycle. As we can see, advances in technology have clearly improved the situation.  

 The subsonic speed resonance in the TT-101 can be seen as periodic cycling every 5 revolutions. If you look at the first traces you posted (yellow) , you will see a positive peak just after 5 seconds. This peak appears again just after14 and 23 seconds. The smaller positive and negative excursions in between these peaks follow the same pattern with their 9 second spaced partners. There is a recurring pattern to the shape of this waveform with a period of 9 seconds.  

 

Cheers,

I introduced this Thread by describing the limitations of the PlatterSpeed App that Michael Fremer has been using for years to test turntables.

The GRAPH produced with the PlatterSpeed App is accurate and USEABLE when looking at the 'Green' Lowpass-Filtered Frequency.
If the hole was PERFECTLY centred.....this 'Green' line would be perfectly STRAIGHT......but only if the turntable was maintaining its speed PERFECTLY.
So the best performing turntables are those with the most constant and even wobbles approaching as closely as possible a STRAIGHT LINE.

The yellow RAW Frequency Plot is what is measured from the 3150 Hz Test Tone and makes NO compensation for the record 'hole eccentricity'.
The 'Green' Lowpass-Filtered Frequency uses the PlatterSpeed Algorithm to 'filter' the 'hole-eccentricity' and produce an accurate graphical plot of the turntable's performance.

If we didn't have the GREEN Frequency Plot that PlatterApp gives us......we wouldn't need PlatterApp at all!!! 🤪
We could ALL just do a Plot of the RAW Frequency response of a random 3150 Hz Test Tone 🤗 

Having been embarrassed by the results of the OMA-K3 compared to the 40 year-old Victor TT-101.....Richard Krebs (the designer of the "most powerful turntable motor on earth") now wants an AUDIT of the 'votes cast' and disqualify those votes shown to be unfavourable to HIS candidate and count only the single vote he believes will allow his turntable to win 😂

The following Plots are done with my 40 year-old Victor TT-81 DD Turntable (bought for $500) with the Test-Disc fixed in one location and the three differently positioned tonearms playing the Test-Tone.

TT-81 with WE-8000/ST 
TT-81 with FR-64S 
TT-81 with DV-507/II  

Note the almost STRAIGHT line of the 'Green' Plot for the WE-8000/ST.
The OMA-K3 can't get close.....

Now the fundamental revelation of these three Plots, is that whilst the YELLOW 'Raw Frequency Plot' varies wildly for all three arms.....the GREEN 'Low-Pass Filtered Plot' remains relatively stable and consequently USABLE!!!! 👏

Richard Krebs however, prefers to make his 'scientific' judgements from ONE meaningless RAW Plot.......🤯

A far more accurate and useful metric of the speed accuracy of a TT is to simply look at the raw yellow trace, ignoring the numbers. How close is it to the ideal symmetrical, clean, constant amplitude, sine wave?

I can't see a clean, constant-amplitude sine wave for the OMA-K3...?

A clean sine wave, symmetrically centred around 3150hz with a constant amplitude for each cycle. As we can see, advances in technology have clearly improved the situation.

 I'm looking for that clean sine-wave but I just can't see it for the OMA-K3?
Please help me here.....🙏