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Hello. This post is about turntable speed accuracy, an issue which I think is quite neglected and little understood.
I will start by saying that I am very sensitive to pitch variations and thus have been struggling for a few years with a phenomenon where my turntables did not sound to me as exact as I think they should be.
I listen a lot to classical music and every turntable I got home was having some sort of sourish sound which was a kind of wow. However, when I asked other people (including one musician) what they thought, they didn't seem to be bothered by it. However, it drove me nuts.
I started to change turntables, thinking that perhaps some kinds are more accurate than others, and already had in my home a Nottingham analogue, Linn Sondek, Lenco l-78, Acoustic Solid (also with battery power), EMT 930 and an EMT 950. I currently own my second 950.
Now I noticed that some turntables did sound at times VERY accurate, like on weekends and late night.At those rare moments, the turntable sounds just right, but then the day after, it sounded "sour" again so much so that I began to believe I was just imagining it was playing right.
I should mention that as I was suspecting that the problem came from power line disturbances, I have tried all sorts of conditioners and power generators - without any effect.
Now, I believe I now know what is affecting my turntable speed.
I have Lately acquired an iphone and installed on it Dr. Feickert platter speed. (on android you don't get the same resolution).
With a test tone of either 1 or 3.145 kh, you can measure you turntable speed and speed variations.
Now the interesting thing is that in most measurements, I get more or less the same statistics with about 0.02% max deviation relative. This seems like a good figure, right? Better than most other turntables. So why the turntable still sounds sourish?
The answer, I believe can be had only when we look at the curve in my attached pic. You see those little twists right in the middle of it, like when the sound goes back and forth? I believe these are my problem. And the proof is that they are not there on the weekend when the speed sounded just right! I have made these measurements a few times and the results are consistent: these disturbances have audible effect and should not be there.
Here are my few conclusions.
1) I believe that many people listen to their turntable not in their right (momentary) speed but think that this is the the proper sound of a turntable. After all, they do today add wow to recordings to make them sound like LP's. Right? wrong. Turntables can sound accurate when played under the right conditions.
2) Line conditioners and speed boxes do not clean the power lines sufficiently well to give the turntable clean electricity.I don't know why but my experience proves this.
3) that even sophisticated turntables like the EMT 950 can suffer from line contamination, although this might be due to its old electronics (mine is not restored).
4) Another conclusion is that wow and flutter measurements do not tell the whole story about turntable momentary speed, which is in my view the important factor and not the average figures (indeed, in my experience, there was no audible difference between turntables with diverse wow and flutter measurements, like the lenco and the EMT, when both were playing late at night!
5) My fifth conclusion is that you never know the real quality of a turntable until you played it in your home with your electricity.
6) There is a review of the VPI direct turntable on Stereophile by Michael Fremer with what looks to me like a very problematic curve. I doubt it comes from this 30,000 turnable. Could it be the electricity in Fremer's apartment is as bad as mine? then what does this say about all his turntable reviews? (if you look at his curve for the Onedorff, this smooth curve is what a turntable curve should ideally look like. I have seen it on other turntables with a much lower price tag).Look at the link.
Thanks.
Follow Ups:
If your LP12 is "Valhalla" powered or more recent then it will have a regenerated supply that was intended to be immune to the vagaries of Mains pollution?Apologies if I misread but did you specify which T/T the 2 tests were performed on?
Edits: 01/09/17
Is your test record centered?
Yes, I noticed the same thing with this app. Any non-centering of the test tone record really screws up the numbers. It is an obvious warble too.
I think the author was pointing to the higher frequency stuff as his concern?
Mike
Dare I suggest that someone is gas-lighting you slowly driving you crazy. Think about it. For most people in this forum, including myself, we tend to be obsessive about our equipment. We would be the perfect victims of someone who wanted to mess with our minds. Now I'm a little sorry that I may have added a little paranoia to the picture.
I will admit that my playback equipment is often subject to pitch variation errors.Have you tried holding long notes?
Edits: 01/08/17
Nt
Thanks for all the replies. I add here the measurement curve from a Saturday afternoon.
I'm with you pitch variation sensitivity,
(I love Hillary Hahn's bright, pitch perfect playing.)
Best result for me has been installing a very robust
battery supply with a significant capacitor bank on my
humble Technics SL 1200 with a Mike New bearing.
Serge Schmidlin, of Audio-Consulting, used to offer this as a kit.
A poor man's version of his take on TT's.
He designs using very low draw direct drive motors,
heavy bearings, battery power supply, and light platters.
My experience at home now is favorable playing content rich,
complex orchestral passages.
Here's the perfect solution to your problem, if not your bank account. I think it's about $30,000. But you won't have to worry about waiting until midnight to listen.
I think there may may be cases of Audiophilia Nervosa, curable only by the $30k SuperPlacebos found in the Stromtank. I choose not to reflect on the demonic specter of micro-micro speed fluctuations. But I may be spoiled because my direct-drive turntables, all my life, have had INCLUDED AT NO EXTRA COST regenerated motor drive power.
Quoting no less of a luminary than Harry Weisfeld: "I believe direct drive is the way to go when it's done correctly. I've always been a huge fan of the concept, but you can't get a belt or a pulley perfect, no matter how hard you try. A belt-drive turntable consists of multiple mistakes and you're always dealing with multiple tolerance errors. Direct drive eliminates these issues." My feelings precisely.
Sure, DD tables also comprise multiple mistakes but I too am very sensitive to PRAT issues and I find, in a sweeping generlity, DD tables by far the most listenable combination of design tradeoffs / mistakes. Yes, I have heard *cogging*-- in DD tables where the motor drive is failing. In a properly operating DD table the speed servo is pure analog and operating in real time;the phase-locked loop allows for no possible cogging.
I think all of us experience periods when our system sounds particularly good - for me often late at night- and other times mediocre. Whether this has to do with power usage, darkness or others factors is up for debate. I do know that my baby grand which is not plugged in anywhere sounds better at night as well. But who knows, maybe humidity is a factor, maybe our hearing changes at times.
Well said. The calmest most regular waveforms may be those in a rested brain without the normal external distractions. This results in no interrupts messing with the CPU, allowing musical enjoyment.
.
"If people don't want to come, nothing will stop them" - Sol Hurok
Everything is always a factor
There are special power supplies for turntables called regenerating power supplies. The produce pure 60-Hz, 115-VAC power by regenerating the the electric signal powering your turntable. VPI and some other companies make these kinds of power supplies especially for turntables. Perhaps you should buy something like this so your turntable would be effectively isolated from noise and other fluctuations on the power line.
Good luck,
John Elison
Nt
Perhaps you should focus on what seems to be your underlying problem by using a power regenerator.
"I should mention that as I was suspecting that the problem came from power line disturbances, I have tried all sorts of conditioners and power generators - without any effect."
It's true that we don't know which models were tried, some would obviously have better isolation from the distortion on the power line than others, but it is difficult to filter out, may require both a good isolation transformer and power regenerator working in tandem, or better yet, a battery supply that is completely isolated from the power line.
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Favorite album of recent times, beautiful and completely mesmerizing: The Revolutionary Army of the Infant Jesus - Beauty Will Save the World
I have tried all sorts of conditioners and power generators - without any effect.
But perhaps not a regenerator like a PS Audio Powerplant.
If he's still getting "bad" power using one of those, then perhaps his home/apartment wiring is the villain.
That's how they work, they generate the AC motor drive using a crystal oscillator as the frequency source. It's just a question of how effective they are.
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Favorite album of recent times, beautiful and completely mesmerizing: The Revolutionary Army of the Infant Jesus - Beauty Will Save the World
As I said before, it would be helpful if the OP provided some details.
Having "bad power" is generally not a good thing for any audio component.
I would get a record with 3.15 KHz tone.
dee
;-D
True terror is to wake up one morning and discover that your high school class is running the country.
quote by Kurt Vonnegut
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