Checking the speed on a high end turntable.

Panotaker

Panotaker

Well-Known Member
I was wondering if anybody has ever checked the speed of one of those high dollar belt drive turntables. If you pull the platter off of a SL-1200mkII, you can lay it on top of your regular platter on your high end table, shine a led flash light or use an orange night light and see exactly what it is doing. I know nobody cares, I was just curious.
 
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You can also use a strobe disc, same principle as the platter dots on the 1200. My VPI Classic is dead on speed wise.
 
Where would one find a strobe disc. I think, or at least to my ear, my Rega is spinning correctly but had the same question on checking speed.
 
Panotaker said:
I was wondering if anybody has ever checked the speed of one of those high dollar belt drive turntables. If you pull the platter off of a SL-1200mkII, you can lay it on top of your regular platter on your high end table, shine a led flash light or use an orange night light and see exactly what it is doing. I know nobody cares, I was just curious.
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that's hilarious!!

I've never heard of anyone taking their platter with them to check speed. :-) Good idea of course, but fortunately the concept started with strobe discs way back when.

Strobe discs are something that I learned about back in the 80s with direct drive turntables being so popular, but I suppose these days it's not something one would find out about through your average hifi store...

good thing we have forums!
 
Panotaker said:
I knew there had to be an easier way. Thanks
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My Lenco came with a little metal strobe disc that sits in the middle of the platter matt, but you may be able to print one out, too. Not sure. (edit..yep..vinyl engine) The VPI is adjustable in very minute increments by moving the belt on the pulley, which is very slightly conical. Simple but effective. I have nothing against direct drives...my Sony 2251 has a strobe, and it's nice to know everything is going the right speed.
 
Danimal said:
Thanks - Website bookmarked!
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cool, happy to help out :-)

those alignment protractors and documents have taught me more over the past couple of months than I knew my entire life growing up with turntables...

worth checking out as well.

cheers,
Don
 
I just printed out that strobe disk and checked it on my SL-1200MKII. The strobe disk is right on the money. I felt stupid asking the question at first, but I figured I wasn't the first one to wonder. I just can't believe I never heard of a strobe disk. Thanks for the link.
Ralph
 
hey man, no worries about asking ever here. How would you have known otherwise? Search tools are good I have to say, but still not perfect if you don't enter the right text, and not knowing the exact question to ask, it's easy to get the search text wrong.

strobe disc would give you lots of results probably. but how would you know to search for "strobe disc" LoL :-)

Isn't the internet a great thing? The main reason I messed up a few turntables (and some of my LPs) back in the 70s and 80s was out of ignorance and no way to get questions answered easily. Pre-internet growing up was a different experience than kids get now days...

cheers,
Don
 
Panotaker said:
I was wondering if anybody has ever checked the speed of one of those high dollar belt drive turntables. If you pull the platter off of a SL-1200mkII, you can lay it on top of your regular platter on your high end table, shine a led flash light or use an orange night light and see exactly what it is doing. I know nobody cares, I was just curious.
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The speed of the turntable is dependent on AC frequency. Wouldn't your AC light and your AC motor be off by the same amount?
 
Panotaker said:
I knew there had to be an easier way. Thanks
Click to expand...

The easiest way is to mark your platter or mat, take your wife's or mom's kitchen/cooking timer, put it in 1 minute, when the mark passes in front of your eyes release the timer, and count how many times the mark passes in front of you, when the timer rings stop counting. Counting 45 is easier than 33-1/3...:D
 
The strobe thing works me for.

Of course, you could always time a song against its official playing time....but I always wondered - does the timing start from the first note to last, or first groove to last?

God I'm in danger of becoming what I always feared. Best step away from the quicksand.....
 
Panotaker said:
I was wondering if anybody has ever checked the speed of one of those high dollar belt drive turntables. If you pull the platter off of a SL-1200mkII, you can lay it on top of your regular platter on your high end table, shine a led flash light or use an orange night light and see exactly what it is doing. I know nobody cares, I was just curious.
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Your light source has to be plugged into a 60hz power source to work. A battery operated flash light will not work.
 
I made a simple strobe for near free. Had a wall wart adapter that puts out 3v AC. It is important that it is AC output. 3V was perfect for a regular bright blue LED I had in a parts box. With a higher voltage output you would need a resistor. Tested it easily by putting the LED into the adapter plug. When I got it right, I simply taped and shrunk the LED right on. Just plug it in and you get a bright 60 Hz strobe. John
 
Bob_in_OKC said:
The speed of the turntable is dependent on AC frequency. Wouldn't your AC light and your AC motor be off by the same amount?
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ac motors can fluctuate a TON while the ac current's frequency remains stable. in north america at least it's been noted elsewhere in AK that the ac line frequency is very stable. and many motors aren't actually driven by ac speed.
 
Don't actually need a strobe to accurately test turntable speed a stopwatch will do. Put a mark on the platter (or on the side of the platter if you want to check speed when playing a record). start stopwatch , count 100 revolutions and hit the stop watch as the 100 th revolution is completed if you got exactly 3 minutes your turntable speed is dead on for 33/13.

I learned some interesting things by following this method. There is slightly more drag on the outside track of a record so that it took 180.2 seconds to finish 100 revolutions 33.2963 RPM. On th inside track it was 179.89 seconds or 33.3537 RPM for an average of 33.325 or an average of 99.975% accuracy. Good enough for me. Above results on my Rega P3. Incidentally, when testing with a strobe disk it was dead on. Since I cant play a record and look at a strobe disk at the same time on my Rega that drag effect was obscured.
 
ejman, yea that works great in a pinch. the more revolutions you test the more accurate your measurement can be, too.

Also, listening to the pitch of the playback is generally a pretty obvious way of knowing if it's right or wrong. But I suppose some people can't tell that kind of thing. Either way some kind of test like a strobe or ejman's idea is kind of a comforting thing to do every once in a while :-)
 
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