Wow and flutter Rega P7 and P9, anyone measure?


I measured on a Rega P5 using an AP test LP "wow and flutter" which is a 3150 Hz tone with a Fluke Multimeter connected to the speaker terminals. I noticed the frequency varied between 3145 and 3155 Hz (estimating since I dont know how fast the digital readout is sampling). Would the wow and flutter be estimated at 10/3150 = 0.32%? This was using the standard Rega belt (black) and stock subplatter.

With the use of two belts on the P7 and P9 has anyone taken direct wow and flutter measurments? Wondering if the results were lower?

thank you
-Theron Day
128x128theron_day
Your number of 0.32% could maybe be defined as "short-term speed deviation" .... with "short-term" being defined by the Fluke meter's ballistics on the short limit and how long you looked at it as the long limit.

But wow & flutter is measured very differently: the test tone is applied to an FM discriminator (similar to the circuit that demodulates the audio in an FM tuner), and the reading is taken from its output. And in order to have any correlation with anybody else's numbers, very specific filters are applied to the signal before the discriminator as well as the discriminator's output, and the meter's ballistics (i.e. peak or averaging) have to be carefully defined.
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Elizabeth that is a scarry issue pertaining to your P5. I like that table but would be concerned if I were to purchase one .

Chuck
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Elizabeth thanks for the information ..... I am thinking of purchasing a vpi classic instead of the Rega.

Chuck
... I am thinking of purchasing a vpi classic instead of the Rega.

Smart choice. Rega's are over-rated IMO.
A more optimistic spec would be that if the motor speed mean is 3150 Hz, then its variance is +/- 5 Hz, or +/- 0.16%

I personally feel that you don't need much speed deviation to hear it on solo piano or vibraphone (I listen to a fair amount of jazz). I also suspect that small speed deviations interrupt pace and rhythm in ways you might "feel" more than specifically hear.

That's why at my budget I like my Technics SL1210, and did some inexpensive tweaks to control resonances and vibration. It's easier/cheaper to mod a Technics to improve inner detail than it is to modify a <$2K belt drive 'table for better speed consistency.
Notec

Thanks..... Plus I think their tables are cheaply constructed too much plastic. Classic 1 is on its way.
Received my classic 1 hooked it up and man is it ever a great table. Glad I made the purchase.

Chuck
A magnetic base/dial indicator can be used to check a turntable's platter for flatness.
http://grizzly.com/products/G9849
I saw a similar indicator at Sears just the other day