Turntable speed test

Print the strobe disc, put it on the platter and light it with an ordinary lamp. The ring for your speed stands still when the speed is right; the rings beside it tell you by how much it is off, and a stopwatch tells you the rest.

Mains frequency where you live

50 Hz 60 Hz

60 Hz: North and Central America, Brazil, Colombia, Peru, Venezuela, Ecuador, western Japan, South Korea, Taiwan, the Philippines, Saudi Arabia. 50 Hz: Europe, Argentina, Chile, most of Asia and Africa, Australia, eastern Japan.

Paper

A4 Letter

Print at 100 % ("Actual size"), not "Fit to page". The bank-card box on the sheet checks the scale.

What each ring means

33⅓ rpm — 180 bars: still at 33.33 rpm
33⅓: 1.1 % slow — 182 bars: still at 32.97 rpm
33⅓: 1.1 % fast — 178 bars: still at 33.71 rpm
45 rpm — 133 bars: still at 45.11 rpm
78 rpm — 77 bars: still at 77.92 rpm

How far off, exactly

Watch the ring for your speed and time how long one bar takes to move to where the next one was.

Seconds per bar

The bars move

with the platter against the platter

Enter the seconds to see the error.

Preview

Ready-made strobe discs

Free to print and share; link to this page rather than to the files.

50 Hz · A4 (PDF) · Letter (PDF)
60 Hz · A4 (PDF) · Letter (PDF)

How to check turntable speed with a strobe disc

Print it at the right size. Choose 100 % or Actual size in the print dialog. The bar count, not the size, sets the speed each ring reads, but the bank-card box tells you the printer did not shrink or stretch the sheet.
Put it on the platter. Cut out the disc and its centre hole, and lay it on the mat over the spindle. A record underneath keeps thin paper flat.
Light it with a lamp on mains power. The bars only freeze under light that flickers with the mains: an incandescent or halogen bulb, a fluorescent tube, or a cheaper LED. Good LED bulbs and daylight do not flicker, and then every ring just blurs. A desk lamp a little above the platter works best.
Play and watch your ring. Start the turntable at the speed you want to check (no stylus needed) and look at that ring. Standing still means the speed is exact. Bars creeping in the direction the platter turns mean it runs fast; creeping back means slow.
Read how far off it is. If the ring marked 1 % slow or 1 % fast stands still instead, that is your error. For anything smaller, time how long one bar takes to move to the next one and type the seconds into the calculator above.

How accurate does the speed need to be?

Makers quote speed accuracy in their specifications. Pro-Ject, for example, gives ±0.50 % at 33⅓ and ±0.60 % at 45 for the Debut Carbon EVO. A deck within about half a percent sounds right to almost everyone; at 1 % the pitch is a sixth of a semitone flat or sharp, which trained ears and anyone playing along with an instrument will notice. A speed that wanders (the bars swing back and forth instead of drifting steadily) is a different fault, wow, and usually points to a worn belt or a dirty pulley.

Source: Pro-Ject Debut Carbon EVO instructions, technical specifications

If the speed is off

Belt drive: A belt that has stretched or gone shiny slips and runs slow, often with wow. Replace it with the belt the maker lists for your model; many decks also have a speed trim screw described in the manual.
Direct drive: Most have a pitch control: set it to zero (on decks with a quartz lock, switch the lock on). If the speed is still off with pitch at zero, the deck needs a service.
45 rpm runs fast or slow but 33⅓ is right: On many belt drives 45 uses a different step of the motor pulley or a separate trim. Check the manual for a 45 adjustment before you blame the belt.

Turntables →

Questions about turntable speed

Why does the 45 rpm ring on the 50 Hz disc say "still at 45.11"?

A ring needs a whole number of bars. Under 50 Hz light (100 flashes a second) exact 45 rpm would need 133.3 bars, so the ring has 133 and freezes at 45.11 rpm. At exactly 45 rpm its bars drift slowly backwards, about one bar every four seconds, and that is correct. On 60 Hz the 45 ring is exact: 160 bars.

Nothing stands still and every ring is a blur.

The light does not flicker. Daylight and many good LED bulbs give steady light, so a strobe disc cannot work under them. Use an incandescent, halogen or fluorescent lamp, or try a different LED bulb.

Do I need a stylus on the record?

No. The disc only has to turn on the platter. Leave the arm on its rest, so the stylus cannot catch the paper.

Can my phone measure the speed?

Phones can, by laying them on the platter and reading the motion sensors. We are testing a version of that on this page; until it has been checked on real turntables, the strobe disc is the measurement we stand behind.

How do I know if my mains is 50 or 60 Hz?

By country. 60 Hz is used across North and Central America, in Brazil, Colombia, Peru, Venezuela and Ecuador, western Japan, South Korea, Taiwan, the Philippines and Saudi Arabia; almost everywhere else uses 50 Hz, Argentina and Chile included. If you pick the wrong disc, no ring will stand still at a speed that makes sense.

Running at the right speed?

Point your phone at a sleeve and VinylAI finds the exact pressing and what it's worth.

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