A bit of stroboscopic trickery,or how to check a record player's speed.

[shesnailie]

The turntable of mine actually has the stroboscope and pitch controls built in. Made by Technics sometime in the 70s or 80s. Found in the wild sometime in the 90s.

[AG3304]

@shesnailie Sounds good to me.Even some fairly cheap Philips ones had this pitch control feature,it was only fitted to those with the little DC servo motor mind.This was the same sort they put into their cassettes at the time,and the odd reel-to-reel.

[Josephharpermusic]

Ya have a great voice mate. Where abouts Britain are you from? I am American, but just spent two years living in Southampton and London.

[AG3304]

@Josephharpermusic Thanks for that,l Came originally from Cornwall,now in East Sussex,about 60 miles from London as it goes.

[dunstun365]

Thats why fluerescent lights flicker which hurts my eyes.

[AG3304]

@dunstun365 Quite right.On the older London Underground trains,a special Motor-Alternator set was used to run the striplights in the cars,at 400 CPS.This was done to avoid interference to signal circuits,and those 400 CPS lights never did bother me like a normal mains one does!

[clydesight]

I did this with this pretty much like you said.

I'm in the US, printed the disc, and put it on a turntable with the record on it (some turntables alter speed slightly when a record is on it) and used a "shop" style fluorescent lamp. Worked fine for 60 cycles.

I agree, the energy saver lamps don't work (and my light correcting energy saver corkscrew bulb hums on top of that!)

[AG3304]

@clydesight l couldn't see why it'd not work with a fluorescent lamp.Glad it did mind!

[clydesight]

@AG3304

In the 1960's they used to sell strobe kits for turntables and tape recorders. They came with the disc and a little neon bulb. Popular Mechanics magazine did an article telling people that if they had a regular fluorescent fixture (in those days, there were no energy saving bulbs) they only needed to buy the disc. Many kitchens were lit by fluorescent fixtures.

Problem? Only high end turntables had pitch adjustments!

[AG3304]

@clydesight l remember those things.Not much you could do with a sluggish shaded-pole driven one if it was all as free to run as it should be! Philips units with the DC motors sometimes had a pitch control on top,otherwise you'd to open it up and do it from the control module...

[clydesight]

@AG3304 I recall a cheap Lafayette record changer I had. I did a strobe test on it and it was slow and had a bit of flutter. I took off the platter and got the main bearing racetrack out. The grease was really gooey and sticky. I cleaned it and lubed it and the thing ran on speed with no flutter that I could see. Sounded better too. It was fun to leave the strobe on and make it try and change a record, the readings naturally went wild!

[AG3304]

@clydesight l've just done the same thing with a friend's BSR deck.They always seem to need a good cleanout and relube,but now it runs spot on.The strobe readings while changing were how shall l say,erratic? :-)

[vwestlife]

If you want to be really exact, it's best to put the paper strobe disc on top of an LP that's playing, because the weight of the LP and the friction of the stylus in the groove can actually slow it down slightly. This effect will be more noticeable on turntables made using cheap plastic components, compared to ones using a good, strong motor and a well weighted metal platter.

[AG3304]

@vwestlife Good advice there.No such trouble with the Philips with its metal platter and AC shaded-pole motor mind,but certainly worth keeping in mind for the cheapo models.

[AG3304]

@triangman1992 Thanks,l remember BIB made head cleaners and such like too.As you say remastering those tapes is a bit of a black art,and the machines have to be spot on for it to be right!

[BadEditPro]

I have close to perfect pitch and I can spot a speed problem in about 2 seconds... I still need the strobe to get it dead on. For tape, I run a prerecorded tape and a CD at the same time and adjust until the beats ,match over about a minute. That gets it just about perfect. :) JC

[AG3304]

@BadEditPro That's good,but l still find the strobe very useful myself too.As for tapes,well it'd take too much messing about to get it to start at exactly the same time as a CD,l'd not have the patience! :-)

[BadEditPro]

@AG3304 It's not as hard as it sounds... :) JC

[raymondleeleggs]

On a cassette deck I play a tape and turn the azimuth screw with a watchmakers screw driver until it sounds right to my ears! However if its happy hardcore music (sped up techno) , it will never sound right even if the deck is running a the right speed! 

[AG3304]

@raymondleeleggs Oh Gawd,all that techno stuff'd probably sound better if played backwards.

[agfamatic91]

thenks for mention me

[AG3304]

@agfamatic91 No trouble,without you,no strobe disc!

[Lachlant1984]

I've seen a number of turntables with those little neon pilot lights on them, I think some of them were made by Technics. What about performing this procedure using a high wattage halogen light? I use a few CFL's around the house and you say they're no good for this kind of practice. If you're calibrating a battery operated record player using this technique would you need to plug it in so you're getting the mains fequency, or would running the unit on batteries do the job?

[AG3304]

@Lachlant1984 A halogen lamp would be okay,as there's no transistorised inverter in them.l remember the Technics decks with the neon lamp,and they were probably okay to set it by.Other makers used to just paint a strobe on there which made it look more expensive than it was,and couldn't be relied on for accuracy.With a battery player the same technique can be used,it's the turnable's speed that matters rather than the motor system driving it,so batteries would be no problem.

[legOldtimer]

Hi River, I am very curious about the speed of the steam-punk player. Are you going to film that to? The 2 Sony record-player I have, have strobe-disk build-in. The first one has a crystal controlled speed direct-drive motor. It was (1978) very expensive and I use that one for my 33rpm record collection. The second player is also direct-drive but it speed is adjustable. I converted the 45rpm electronically to 78rpm and there I use a strobe-disk to see if the speed is correct. Warm regards.

[AG3304]

@legOldtimer Hi Ben,no haven't got round to that just yet!The two Sonys you have sound to be very good decks.Sony always did make good stuff back then!

Warm regards,River

[78rpmblog]

I've used that software too and it is very useful.

[AG3304]

@78rpmblog Certainly is!

[rich3500]

My late Uncle had a turntable with this facility built in like CoolDudeClem mentioned below. My Dad had a Logic turntable which cost a fortune and was always spot on for speed, it used a synchronous motor with precision machined pulleys and stainless steel turntable that was belt driven. To change from 33 to 45rpm you just moved the belt onto a different pulley. The turntable was so heavy it took about 10 seconds to get up to speed. This was around 1980; a new one today would cost thousands!!

[AG3304]

@rich3500 You used to see this on the more upmarket or top end decks.Others may have had the markings,but weren't right,just making it look more expensive.Your late Uncle's one must have cost a tidy old bit then,and as for now,well l dread to think!The turntable would've acted like a flywheel l guess,and l bet the whole weighed a ton!

[donkeywarmer]

didn't know about this, thanks for shareing

[AG3304]

@donkeywarmer No trouble

[CoolDudeClem]

I remember seeing some tuntables with this buit in, not truntables with their own built in neon light and shiny dots at the side of the platter, but the stroboscoping thing built onto the top of the platter. BTW you'd make a much better president/primeminister (or whatever we have now) than whos running the country at the moment.

[MarkPMus]

@CoolDudeClem Thanks for retweeting this Clem - it's a great video, and I'd not come across this YT member before!

[AG3304]

@CoolDudeClem Been an age since l saw one like that l can tell you.Me as President/Prime Minister?That'd shake the buggers up !

[pooface006]

nice video ,i really liked it!

you might be able to convert

the record player to run on a

dc motor

[AG3304]

@pooface006 Thanks,glad you liked it. Well the player's speed's so nearly right l'll probably leave well alone for now.

[matthewpeter]

good old bulbs, the new "eco" bulbs are dire.

[AG3304]

@matthewpeter Mine take about 3 minutes to warm up generally!