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variance of +/- 10 Hz with 1 kHz test tone

I tried the Dr. Feickert Speed Tests iPhone app. I don't have his test record for the 3150 Hz track and the app says that you can use a 1000 Hz tone. I have a 1000 Hz tone from the Clearaudio sweep / burn-in record and tried that with the iPhone app running and showing microphone input on the meter. The app registered nothing. Has anyone else been able to get his iPhone app to work with a 1000 Hz tone? Are there any known problems with this app on iOS 7?

I used another iPhone app "Tuner Lite" and it showed my table to average right on for a F# 5 with the tuner set to concert A 440 Hz using the 1000 Hz tone. The Tuner Lite meter did fluctuate between the sharp and flat side (again within the two inner arrows, about +/- 10 Hz and were equidistant on both the flat and sharp side) during even time slices / cycles. Is this wow? Flutter? Good, bad or indifferent? Hole off center on test record? Strobe 33.3 reading looks to be dead on using the same Clearaudio disk with stylus on the record.

Phono setup is:
RP6 with GT ref subplatter and TTPSU
Herbie Mat Way Excellent II-2mm
Audio-Technica AT-33PTG/II 0.3mV MC
Salience / Jasmine LP2.0 mkII

Thanks,

Scott
sbrownnw
gvasale's avatar
gvasale
99 posts
 
If I'm not mistaken that level of performance translates to .02% away from what a casual internet search showed to the best to be, a VPI TT with .01%

Anything that bests .1% exceeds NAB specifieations.

"Wow and Flutter Factor (Re~ording)~
1.15 It shall be standard that the average deviation (measured over the range 0.5-200 cps)
from the mean speed of the recording turntable, when making the recording, shall not exceed
0.04% of the mean speed. The average deviation above shall be measured by a meter the dynamics
of which shall be the same as those of the VU meter as specified in ASA Standard C16.5-
1961.
Wow and Flutter Factor (Repr~ducing)~
1.20 It shall be standard that the average deviation from the mean speed of the reproducing
turntable when reproducing shall not exceed 0.1% of the mean speed."

I can't remember anything that would suggest the NAB would want to drive listeners away from either Am, FM radio because they were sloppy or uncaring with audio performance.

Because today, many turntables routinely perform in the range of .03% or less can't possibly mean your head might spin when listening or that performace in the .03% to .01% isn't top notch.
atmasphere's avatar
atmasphere
11,783 posts
 
That's about 0.1% isn't it? maybe sounds a little on the high side...
sbrownnw OP
692 posts
 
@Gvasale and @Atmasphere, what is the formula you are using for these calculations?
gvasale's avatar
gvasale
99 posts
 
Apologies apparently are in order. That amount -/+ 10 Hz is really 20 Hz because it is going from 1000 to 1010 to 990 and in between. I left off the % multiplier which changes it signicantly. 20/1000=.02x100=2%

Still, listening will give a good picture. Excerpt from NAB is correct. Ive been trying to increase a 1Khz tone with the signal generator (True RTA) but I can't move it in 1 hz steps to see how noticable it is, and my old analog signal generator has no way to accurately do the same as well.

Again, my apologies.
sirlordcomic
21 posts
 
I found the Feickert 7" (my copy) tone to have a lot of inherent wow, it's off center or something. For example, if you are at 33.33 you'll see the bar go all the left/right edges of the green section.

The UTR 3150hz has much less sway back and forth in the Platterspeed's meter. It will do a much tighter measurement which looks more like the demo if you have run that in the app.
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