What's the speed of your turntable?

I don't know, actually. Since my 2m Blue bit the dust on my Xpression III, I brought out my Dual 721 with a Shure m97xe to tide me over. The Dual doesn't sound like it is keeping time anymore... quite a bit slower.

 

What is the speed of my turntable? It is zero mph; it has been sitting in the same spot for years. The speed of rotation is something I don't care about as long as it is within 2% of the nominal value. What IS important is that short-term speed changes that result in wow or flutter be kept at a minimum; long-term average speed doesn't matter nearly as much. It seems to me that way too much attention is paid to long-term average speed, probably because it is so easily measured.

 

Well, since I live in Houston at a latitude of about 30 degrees north, my turntable is going about 20,800 mph. It's flyin' baybee! But I am as well.

 

Yard sale special Kenwood. 33.34 and 45.01

 

My 25-year old belt drive runs about 0.3% fast: plays a 1 kHz tone at 1003 Hz. I only use it now for needledrops so I speed-correct it in Audacity. I've already turned it into numbers so what more harm can be done by moving those numbers a bit?

 

I run an old Dual 1019, which has that fine-tuning knob, so what I did was put on a song I knew extremely-well on my digital music server setup and kept adjusting the fine-tuning knob until I was dead-sure that it was running at the same speed. Being a musician, I have a really-good ear for pitch, so I'm able to set my turntable by ear. Once I did it the first time, my 1019 has run dead-on ever since. I love the motor in that thing. It's huge.

Here's a picture of a custom-built 1019 that shows the size of the motor well.

 

Technics SL-1200M3D with Audio-Technica AT-150MLX via Turntabulator in Exact mode on iPhone 6S with stylus in groove:

33.33
45.01

 

On my Technics SL-220 I get 33.37 when the strobe is steady, using the free RPM app. Will check my Dual quartz-lock later and post.

 

I have a Pro-Ject Xtension 10 with the built in speed box (Speed Box DS). The platter weighs 5.7kg and there is an additional record weight that is pretty heavy, so the weight of my iPhone is insignificant (I would think). I've checked it with a strobe disc and it seems right on. But mainly out of curiosity, I downloaded the two apps for iPhone that I could find that do not require a test record.

The RPM app:
RPM - the turntable speed accuracy checker. on the App Store »
reports the speed is 1.8% high (33.9 rpm).

The Turntabulator app:
Turntabulator on the App Store »
says it is right on (exact) or sometimes 0.1% high or low.

The RPM app says it uses the gyro and warns about inaccuracies:
"The iPhone gyroscope is very accurate, however if you are in any doubt you should calibrate RPM first using a quality turntable of known rpm."

The Turntabulator app says it doesn't use the gyro and is more accurate because of it:
"Through the power of Musical Analysis with Gyroscopically Indifferent Calculations (MAGIC), no gyroscope is required, so Turntabulator works just fine on the iPhone 3GS. In fact, the results are more accurate than the iPhone or iPod Touch gyroscope would provide."

Based on my sample size of one, I'd have to say that the Turntabulator app is accurate, and the RPM app may or may not be depending on your phone (mine is an iPhone 5s). I tried both apps with the phone centered on the record weight and near the edge of the platter and it didn't affect the readings at all.

Terry

 

It depends...

 

Should I be worried?

 

14.6 percent too slow. You were measuring 78...?

 

It's a bit off but it makes those Jamaican 45s sound extra mellow

 

I dont have a way to test mine Paul but all speeds sound like they are where they are supposed to be... (My crosley though is too fast (I dont use it much anyway))

 

My Pro-ject Debut Carbon Esprit SP DC runs at exactly 33.33. Take that, Rega owners!

 

I've checked my Pioneer PL-S40 quartz lock a few times with RPM. It's been 33.29, 33.33 and 33.35. No idea which is correct.

On my Realistic LAB-300 I was getting 32.?? so I got a new belt. The new belt was quite a bit tighter and the tt ran even slower. This bugged me so I wrapped a tiny bit of teflon tape around the motor shaft to correct. It took a few times of too much tape until I got it just right, or close enough at 33.35.

With no idea whether the app is accurate or not, I'm leaving it alone.

 

RPM was very accurate on my android phone. Never got different readings.

Going to compare to Turntabulator on iPod 5.

 

I have a iPod 5gen, Samsung s4 and Samsung Note 4.

iPod rpm & turntabulator app and note 4 rpm calc app read the same.

S4 rpm calc app reads 1.0 faster on both 33 & 45.

 

Turntabulator said 33.2?? But RPM said 33.45

I'm not sure what to believe.

EDIT: iPhone 6s

 

I would believe the Turntabulator app. The RPM app warns that inaccuracies in the phone's gyro can affect the accuracy of the reading. The Turntabulator claims that it doesn't have this issue.
This is certainly the case with my iPhone 5s. The RPM app is inaccurate (compared to a speed disc and my speedbox ds on the turntable). The Turntabulator looks spot on.

The RPM app says to calibrate it against a turntable of known rpm, but I don't see any way to do that (other than just mentally offsetting the readings).

Terry

 

Visually, the difference (OK, not the ultra-accurate difference) is clear between 33.2 and 33.45. Take a record with something in the label design that serves as a pointer to you (the classic "blue sky" Asylum Records label comes to mind) and take one minute of your time to count the turns while staring at the record and checking a stopwatch. When it reaches the 33rd turn, watch the pointer and see where it lands when the stopwatch gets to 01:00. At approximately 12 minutes (clock minute hand), it will be roughly 33.2. And at approximately 27 minutes, it will be 33.45.

That's what I did in the (very) old days to check the speed of every record player at home. You won't get an ultra-precise reading but, since you say you don't know what to believe regarding the differences between Turntabulator and RPM, this method should be enough to make your mind up.

 

I bought a used Kenwood KD-291R bought cheap from shopgoodwill.com; I'm using an RPM app, and it's running lower than 32 rpm and not at 45 either. Been searching all over the internet trying to find out if there's any way to fine tune the speed, but am not having any luck at all. I guess you get what you pay for. Need to think about investing money into a quality turn table.

 

Download the service manual online. There are a couple sites that offer them if you register.

Usually it is pretty easy once you identify the pots to turn to adjust speed. Don't give up on it, it's an easy fix.

 

My Rega P25 consistently spins at 33.75, or 1.26% fast. Certainly a well known issue.

 

I found both the user manual and service manual on line, but the only reference there is to adjusting turntable speeds has a short and extremely vague statement with no details or procedures. I opened up the underside and couldn't even find the two areas it mentioned.