Not true for my results. My AR is a tiny bit high as is my ST-7. The first has no adjustment or strobe and the second has both. Most of the rest are spot on and agree with the strobes. The Denon is a bit slow.
Platter spins at 33.4
- Thread starter truckrglenn
- Start date
Not true for my results. My AR is a tiny bit high as is my ST-7. The first has no adjustment or strobe and the second has both. Most of the rest are spot on and agree with the strobes. The Denon is a bit slow.
I tried two of the top contending apps on the Play Store. They both gave the same results. An average of 33.24 same for wow when testing with the strobe spot on. .24 is fine, .09 isn't enough to worry about. I wonder what the tolerance is on those apps as well as on the adjustable strobe on the Denon DP-30L. The apps are accurate. Quite a brain fart testing at 33.01. Interesting thread.
When cleaned and lubed the Denon gained speed but I can't rule out hitting the speed adjustment wheel with an errant finger during that process. Had to readjust.
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tnsilver
Stereo Puppy
It's hard to notice on a strobe.
Both apps use the same hardware. The point is comparing different apps on different phones, even same apps on multiple phones. I guaranty you won't get the same results.
It's hard to notice on a strobe.
Both apps use the same hardware. The point is comparing different apps on different phones, even same apps on multiple phones. I guaranty you won't get the same results.
It was checked with the phone app with the phone on top of the record clamp. Didn't change one whit when the needle hit.
flavio81
Turntable technician
Hi Montycat,
For what it's worth, here's what i get on my non-servo Sony PS-2310:
Wow (2-sigma): 0.15%
Wow (RMS): 0.10%
Conditions:
- Not precisely leveled, just more or less leveled.
- Belt way too tighter than it should be
- Belt still makes some noise (not good)
- Belt absolutely clean but without talcum. With talcum the figures were way worse (go figure)
- Badly relubed bearing (there's some play left so i'll have to try higher viscosity oil)
- Cell phone on top is probably creating part of the wow, it's very hard to balance it so it doesn't influence the result.
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Oh my! yur logic is impekable proly should say me sorry. Then again maybe not.
twiiii
Lunatic Member
If you had perfect pitch or great relative pitch you would have picked up on the issue much sooner. Since you don't, son't worry about the 1/3 of a percent error. Let's see that would make A 440 an A 441.1 HZ which is below A 442 to A444 European pitch. In other words, don't sweat the small stuff. Just enjoy the music.
tnsilver
Stereo Puppy
You go through the trouble of mentioning the 2nd decimal point (33.01 RPM, wasn't it?) of your measurement, but for some obscured reason stylus drag goes unnoticed... It is a real thing you know. It can account for up to 5% of speed slowdown and yet your app doesn't see it... My logic is just fine - thank you. The phone is likely less so.
flavio81
Turntable technician
I always understood that the cell phone had to be precisely over centered and well balanced. Which is very hard to do.
Thus, one of the problems with these apps is that the imbalance created by an off-center phone will influence the result. Of course, depending on the turntable since -for example- all direct-drive turntables have a servo and will automatically correct for it. Some idler wheel turntables have such powerful motors that won't be influenced either.
Now, many belt drive turntables will be influenced by an off-center cellphone.
The app is more precise than the strobe for measuring turntable RPM over one turn.
Which turntable was it?
Depending on the turntable stylus drag can be become very real and easily measurable, or absent, again for the same reasons mentioned previously: Servos, or very high torque. Or even if the platter is very massive and thus the cellphone becomes like a fly trying to move a pyramid.
I'm sure most are aware of the limitations of using these apps. If you use a record clamp and put your phone on top of that, not that hard to center it.
Who and why would anyone care about this.
Denon DP-30L DD.
Where did I ever say that this included all turntables. I just related what I experienced with mine. Really the tangents people can get off on.
flavio81
Turntable technician
I understand you mean a "servo" here, not just a simple speed controller.
Yes, it will help you get the average RPM of the turntable correct, however if you make it able to "instantaneously" correct for drag caused by signal modulation, you will be "instantaneously" modulating the platter speed too. Which is detrimental to sound quality.
There is no better solution here other than... big torque... Platter mass helps too, however IMO it's not the best solution.
flavio81
Turntable technician
Anyone who is doing transcriptions will care. You want to transcribe at the exact speed.
As i wrote: all direct-drive turntables have a servo and will automatically correct for it.
adnick
Addicted Member
Yeah use the term speed controller to be inclusive of different types, but you missed my point, I’ve yet to see a table that didn’t respond to needle drop even my heavy platter big motor tables, think ROK TR12H, and such….tables like my Denon DP 75 just overcome and stabilize extremely quickly, it’s not detrimental to sound quality.
Andy
tnsilver
Stereo Puppy
Yes, me too. The drag is always there. If one can't see it - the measurement is at fault.
And if you transcribing you'll pick the table you need. Moot point. One thing you could tell me is what is the average loss of speed to needle drag.
As I know. How do you not see that.
Had a fair amount of TT's since 1976 and stylus drag hasn't affected my listening ever. So I'll leave you guys to your minutiae.
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tnsilver
Stereo Puppy
There's no average! It depends on the content, i.e the groove modulations. It doesn't really matter. If you stick to a figure like 33.01 RPM, emphasizing the second decimal point, which is 0.03% of the measured speed, you should also be able to measure stylus drag. That's true even if I'm 100 times wrong about stylus drag influence on the speed. It just doesn't makes sense for you not to see it - which is why these apps on certain phone are simply unreliable. I wasn't kidding about banging a phone once too many. It can destroy the accelerometer crystal and it generally places it out of kilter.
MuseChaser
Super Member
Anyone with perfect pitch, especially those of us who tried to transcribe any portions of that side. A horn player friend of mine wanted me to play Bill Evans' intro to "So What" exactly as Bill played it (or as close as a mortal can come to recreating Bill's genius). Transcribing those "in the cracks" tracks was a nightmare.
I recently picked up a very high quality vinyl reissue, with the speed corrected on that side. After listening to the album at the wrong speed for 50 years of my life, the "right speed" now sounds wrong to me, however. I love the sound of this new pressing... It's gorgeous... But the pitch change, well.... Changes the feel of that side, and I wish they had left that part as originally issued.
There are stories that the altered speed was intentional on Miles' part; that he was unhappy with tempos chosen, or preferred the darker sound of the off-speed. Most discount those tales, however, and chalk it up to an uncalibrated deck. To be honest, neither explanation makes much sense to me. Maybe we'll never know for sure.
An all-time, legendary hallmark album. I've literally worn out two copies, and have two more on vinyl and a CD reissue.