advertisement


What is a good phone app for turntable speed accuracy

P

per-Sony-fied

Me in another jacket
Having recently being playing about with my turntable fitting the Karousel & John R's Sole subchassis I've reached the set-up point for checking it's speed accuracy. I have been over to Vinylengine to print out a strobe disc but have no strobe to check it lol!

I had a play last night with a couple of apps, both came up with the same result where they reported speed to be 33.5 RPM :eek:, no idea if this is right or wrong. These were Turntable speed & RPM calculator. Measurement was taken placing the phone over the spindle resting upon a spirit level/45rpm adaptor.
 
This is a post I made to a thread titled “Turntable Speed”.


I have two apps on my iPhone that test turntable speed. “Turntable Speed” is the one I’ve been using for the tests and screen shots I’ve provided in this thread. It’s a free app and it works great but there is no way to calibrate it to the gyroscope in the iPhone.

The other app I have is called “RPM”. It is also free for 10 uses and those are not calibrated to the iPhone. They have a paid version for $15 that has provisions to calibrate the app to the iPhone. I purchased the app and found that the calibrated results differ from the uncalibrated results.

I did find that the uncalibrated results of both apps agreed with each other. Hope that helps.
 
How does it get 'calibrated' to the Iphone? is there a procedure - what's the 'reference'?

I am curious - because surely the app can only report on what the gyro is telling it - there is no other mechanism that the app can be using, is there?
 
It’s explained in the Apple App Store under the review titled “Nice” where the developer responds. Apparently there’s a variance of tolerance of the gyroscopes between devices. The calibration feature applies a fix factor. If I recall correctly, you run the iPhone on the turntable for one or two minutes in the calibration mode.
 
Phone apps are not super accurate. Certainly not as accurate as a proper strobe disc and zapper if you have an expensive turntable. If you have a turntable where you can adjust the speed, then buy a proper turntable speed strobe disc and zapper. If you can't adjust the speed of your turntable then use the phone app as a guide. If your getting 33.5 RPM with a phone app and you can't adjust the speed, then I would suggest not worrying about it and just enjoy the music...
 
I’ve just re-measured the speed of my TT using the RPM Android app. It tells me it’s averaging at 0.14 RPM, ranging between -23 RPM and +22 RPM. I’m inclined not to believe what it tells me.
 
G T Audio said:
Phone apps are not super accurate. Certainly not as accurate as a proper strobe disc and zapper if you have an expensive turntable. If you have a turntable where you can adjust the speed, then buy a proper turntable speed strobe disc and zapper. If you can't adjust the speed of your turntable then use the phone app as a guide. If your getting 33.5 RPM with a phone app and you can't adjust the speed, then I would suggest not worrying about it and just enjoy the music...
Click to expand...
To be honest I'm not bothered about them being super accurate more concerned how inaccurate they are or can be. Even if you watch a strobed turntable you can never get the dots/lines 100% stable. There's always a small amount of drift after many revolutions.
 
you don’t need a special flashing light to use a strobe disc, just an old fashioned incandescent light bulb.
 
Chris said:
you don’t need a special flashing light to use a strobe disc, just an old fashioned incandescent light bulb.
Click to expand...

True, but that is even more inaccurate than a phone app. You cannot rely on the mains frequency being that accurate. If you have a turntable where you can adjust the speed you definitely need a proper strobe disc and zapper, like the one from KAB.

 
I just used the Android "RPM speed & wow" app on my deck suspected of running slightly slow.
The app confirmed a 1.6 rpm deviation down from normal.
Seems reasonably accurate.
 
cj66 said:
I just used the Android "RPM speed & wow" app on my deck suspected of running slightly slow.
The app confirmed a 1.6 rpm deviation down from normal.
Seems reasonably accurate.
Click to expand...

I use the same app.

I place my phone on top of a record weight to get it centralised over the spindle.
I find the app to be quite useful to dial in the rpm on my turntable and it's reasonably easy to use.

I do have a stroboscope disc, but the gadget that shines a light on the disc doesn't work anymore. Too much faff to find a new device.
 
The Android 'Speed and Wow' App doesn't completely agree with the strobe in my TD124 in terms of RPM readings but the wow measurements do seem very repeatable and consistent.
 
You must log in or register to reply here.


advertisement


Back
Top