Platter spins at 33.4
- Thread starter truckrglenn
- Start date
Not having a lot to do today and just for the heck of it I decided to check some of my turntables with my Pixel 7 Pro. The results are about what I expected.
They are pretty consistent but it would be interesting to see if the wow figures would be less if there was a way to get the accelerometer positioned exactly over the spindle. I bet some of the variability can be attributed to it being not centered.
The belt drive AR has an oldish belt and had very little attention or recent use and has no speed adjustment. The other belters (ST-7 and PS-2400) have strobes, older belts and were somewhat dialed in. The SP-15 was tested with Quartz Lock on and off. The KD-650, PS-X600 and Denon are QL only. The 1229 is of course idler drive with strobe.
They are pretty consistent but it would be interesting to see if the wow figures would be less if there was a way to get the accelerometer positioned exactly over the spindle. I bet some of the variability can be attributed to it being not centered.
The belt drive AR has an oldish belt and had very little attention or recent use and has no speed adjustment. The other belters (ST-7 and PS-2400) have strobes, older belts and were somewhat dialed in. The SP-15 was tested with Quartz Lock on and off. The KD-650, PS-X600 and Denon are QL only. The 1229 is of course idler drive with strobe.
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doctor fuse
Super Member
Everyone says the RPM apps are not accurate, but when I test them they are VERY accurate:
RPM Wow app, on an iPhone 8.
It measures 33.34 RPM on my Denon DP-35F with Quartz lock.
It measures the same with a Technics SL-D2 DD, when the strobe pattern on the side of the platter is stationary.
I wonder if everyone is calibrating their phone’s gyro using a level app? Or if their turntables are levelled well?
doctor fuse
Super Member
0.02%! My Denon DP-35F gets 0.05% and I thought that was good. Have you given your bearings/motors a thorough cleaning and oiling?
No I haven't really done anything to it.
SmileyFaceEQ
Super Member
I have a rush 2112 that is so off center that I thought I was having a stroke.
SmileyFaceEQ
Super Member
I have turntable OCD as I restore them regularly. I have to avoid tables without pitch control. I don't mind a hair of W/F, but it really does bug me if the time is not on.
ejman
Super Member
I get consistent results that match a strobe when using the RPM wow app on my android phone. My best turntable is a Lenco L75 that measures consistently at 0.04 RMS wow. Surprisingly my Rega P3 (with Tangospinner sub-platter and dual belt pulley) measures identical to my Dual 1019 at 0.08 wow. I think the main factor for measuring RPM/wow with a phone app is to make sure that the phone is precisely centered over the turntable platter spindle so the display does not wobble at all.
doctor fuse
Super Member
Din’t forget to calibrate your phone’s gyro with a level app calibration or something similar!
adnick
Addicted Member
Are you guys checking these playing an LP, in other words with the needle dropped?
Speed is close with a well centered device, W&F is terrible, doesn’t match my actual W&F machine at all, and once again the needle needs to be down, however it’s better on the iPhone than it was a couple of years ago, it’s also closer on DD, at least the ones I’ve checked.
VR
Andy
Edit: if one is really serious about speed measurements, it should be an average over 20 minutes or so… Good news is most will be happy with stable speed even a little low/high
Speed is close with a well centered device, W&F is terrible, doesn’t match my actual W&F machine at all, and once again the needle needs to be down, however it’s better on the iPhone than it was a couple of years ago, it’s also closer on DD, at least the ones I’ve checked.
VR
Andy
Edit: if one is really serious about speed measurements, it should be an average over 20 minutes or so… Good news is most will be happy with stable speed even a little low/high
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tnsilver
Stereo Puppy
Yup! Absolutely. Otherwise it doesn't reflect playback speed. Stylus drag counts!
If you have a flat top record clamp, that can get you over center. I tried it and it dropped the wow 2-sigma by 7 to .04 the wow RMS by 5 to .03 probably from the added weight. I also adjusted the speed to where it measured 33.01rpm and the strobe was running backwards. With the strobe stable it measures the rpm at 3.24. I think I'll stick with the strobe.
Just tried it playing a record. Stylus drag didn't make a difference. It's set at 1.8 grams same for tracking force.
Just tried it playing a record. Stylus drag didn't make a difference. It's set at 1.8 grams same for tracking force.
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flavio81
Turntable technician
I think that Sony PS-2400 is in need of a mechanical and electronics overhaul. It was specced for much better W&F figures, actually very similar to the PS-2500 which is very good in this respect.
Very nice machine that deserves some love (Sony fan here.)
Thanks. It hasn't seen much use lately and was just hooked up for this test. I should give it some attention. Aesthetically it's one of my favourites and I even splurged on an expensive dustcover replacement as the original had a damaged corner though was still fully serviceable. Not many people know this model.
flavio81
Turntable technician
T
I have an even rarer model, the PS-2310 which doesn't use a DC motor (w/servo) but a regular AC motor. And I had the PS-2500 direct drive.
Does the bearing in your TT has some play? Those bearings often need a full cleaning and then relube with a suitable oil. Correct oil is "mobil DTE light" but i'm using ATF Dexron III as substitute (documented elsewhere in AK), no play at all.
Belt should be good and tight with no riding up/down and the servo circuit could perhaps do with some refurbishing. The schematics are on the service manual, it's not a complex circuit. There's no reason this TT couldn't get very good speed stabiloty. My PS-2310 is even less sophisticated and it gives very good sounding pianos.
I have an even rarer model, the PS-2310 which doesn't use a DC motor (w/servo) but a regular AC motor. And I had the PS-2500 direct drive.
Does the bearing in your TT has some play? Those bearings often need a full cleaning and then relube with a suitable oil. Correct oil is "mobil DTE light" but i'm using ATF Dexron III as substitute (documented elsewhere in AK), no play at all.
Belt should be good and tight with no riding up/down and the servo circuit could perhaps do with some refurbishing. The schematics are on the service manual, it's not a complex circuit. There's no reason this TT couldn't get very good speed stabiloty. My PS-2310 is even less sophisticated and it gives very good sounding pianos.
Dudeman7
Well-Known Member
I don't have a strobe disc for my Dual 1019 so I just set the speed to where I think it sounds right with familiar recordings.
Just for fun, I checked it with a phone app last night. The result was 33.34 with 0.07 wow.
Pretty happy with that! Even if it was off, I don't think I would have changed anything since I like the way everything sounds on it.
Just for fun, I checked it with a phone app last night. The result was 33.34 with 0.07 wow.
Pretty happy with that! Even if it was off, I don't think I would have changed anything since I like the way everything sounds on it.