Wow and flutter - some figures

[davidro]

Hang on a sec people didn't you guys talk about some mid-frequency W&F issue or something like that that SL-1200 was guilty of which made M Fremer guy's rather low opinion of the table quite valid?

 

[avole]

Hang on a sec people didn't you guys talk about some mid-frequency W&F issue or something like that that SL-1200 was guilty of which made M Fremer guy's rather low opinion of the table quite valid?

Definitely not me, and not perhaps on this forum. I thought (and hopefully demonstrated) the guy was talking rubbish.

 

[lini]

avole: Depends on the model. Of course, disassembling a new turntable in a shop isn't really practical. However, decent reviews/review pics can help there - and many turntable fans are rather interested in older models anyway, for many of which one nowadays can easily find quite a bit of info and documentation on the web...

Nevertheless, you're certainly right, that a decent w&f measurement would be the quicker and more convenient approach - but I didn't claim the opposite anyway. Actually I'd rather suggest a combination of both...

Greetings from Munich!

Manfred / lini

 

[zenith2134]

Remember that the ear is more sensitive to W&F as frequency increases. Find a quality pressing with sustained tones of 10-15kHz on it and make your assessment. Electronic music is ideal for this. I used a promo LP on Duke/Atlantic by 80s group Nine Ways to Win..some of those grooves go very high up and are great for testing cart setup and W&F.

 

[Ed in Tx]

Pioneer in the Tuning Fork #4 elaborated quite a bit on turntable W/F measurement. They said conventional W/F testing was good to about .05% with a test record. With a specially made lacquer test record that could go down to .02%. Then they came up with an optical measurement system to measure down to much smaller variations.

 

[flavio81]

Pioneer in the Tuning Fork #4 elaborated quite a bit on turntable W/F measurement. They said conventional W/F testing was good to about .05% with a test record. With a specially made lacquer test record that could go down to .02%. Then they came up with an optical measurement system to measure down to much smaller variations.

Yes, but this still has the problems i've described, mainly the use of weighting, and of only 1 frequency as the signal.

On the Pioneer Exclusive... an interesting story that shows how manufacturers intentionally change weighting figures for their own benefit:

The Pioneer Exclusive P3 was specified at 78dB weighted rumble, and the new one (P3a) to an unheard of, unbelievable, unheard-of 95dB! What did they change on the turntable? NOTHING. What happened was described as this:

Sometime in the very early 80s, the EIAJ (Electronics Industry Association of Japan) changed their DIN B measurement methodology
to, according to the marketers, 'better measure what the ear hears'. They changed something to account for the shape of the human ear.

Left largely unannounced, they 'flattened' the weighted curve, and added another filter, which had the effect of raising S/N ratios by 'about 20dB' depending on the piece of equipment being measured."

I asked him whether they measured anything when tables came in to get repaired. He said that in fact they measure all tables according to that newer "DIN B (EIAJ, A-network) standard because that is the machine they have now.
When I asked how much better the P3a measures vs the P3, he said, "They come out the same : non-statistically-significant sample difference".


Source: http://www.thevintageknob.org/pioneer-Exclusive_P3.html

So it was still called "DIN B weighting" but, in fact, it wasn't the real DIN B weighting... By the way, saying "DIN B (EIAJ, A-network)" is like saying "red color (50% blue, 50% yellow)".

This is a rumble example, but the bottom line is: when comparing flutter figures, we have to at the very least take note of the weighting used, and if that if there were no hidden tricks...

 

[perryinva]

Personally, the only thing that matters to me is which of my own TTs has better W&F numbers. What do I care what any spec says, when there is no guarantee that the table you own lives up to it? I know what sounds good to me, and what I like, but it would be great to quantify any difference between them. If I could just find an LP with a 3 or 3.15kHz tone to use with my W&F meters then I'd be happy!

 

[slate1]

Pro-ject RPM 9.1 0.08% Manufacturer.

Just an FYI. The 9.1 is actually spec'd at 0.06%

 

[sa-9800]

wtf. You want perfect numbers, get a CD player.