LP12 motor

Quick question, desperately hoping it has a quick answer:

Is the 9904 111 31813 a direct drop-in replacement for the old 04802?

I’m asking cos mine (04802) has stopped turning - I’ve replaced all the caps in the PSU and the voltages are right, the motor doesn’t start but mains vibration is felt on the pulley, it turns if started off by hand but clonks very audibly at every revolution, so I don’t think it’s a simple lubrication issue. There’s no play in the spindle but it does feel pretty stiff to turn.

Any info/advice gratefully received!
Raph

Bear in mind if you change the motor you will have to set up the offsets on the mounting screw balls to calibrate the speed.
You’ll need a strobe light and disc.
Clicky and sticky motors used to always be cured with light penetrating oil down the spindle shaft though the top bearing.
If the deck has a Lingo fitted it might be that the thrust pad on the bottom of the motor is still in place making it tight.
Just twist it off and remove the gubbins sometimes a ball and spring or a composite cone.
Bottom of motor left open.

Thanks! - I assumed the clicking noise was a harbinger of imminent death, but I’ll take the bottom cap off and give the lube a go.

I’m new to this game but as far as I can tell it’s a Valhalla. I can’t upload a pic but it’s the one with the three 47uF caps in a T-shape and the voltage trim pot at the other end.

I’ve just taken the bottom cap off - with the spring, now the motor starts reliably and runs (haven’t checked speed yet), but makes a noise reminiscent of a marine diesel engine at idle. Seriously loud. Not exactly clicking but certainly thumping its way round like it’s towing the QE2.

Worth noting there is no axial play whatsoever, with or without the bottom cap.

PS if it does come to fitting a new motor, I assume the saving of buying a bare motor from RS at c.£100 (as opposed to one with a pulley fitted at more like £200) will be more than offset by the impossibility of transferring the pulley and the likelihood of wrecking both in the attempt?

Best get one even a good second hand one as the pulley is a very tight fit and especially milled to fit at a certain height for speed adjustment.
Your signature says Lingo so the bottom should have been removed.
But you mention Valhalla so I assume your repairing a different deck.

Raph - A bit off topic but the Wilmslow TL12 speakers you have listed in your profile look rather impressive. The driver arrangement and front venting TL look very similar to PMC MB2s. Very nice.

Good luck with the motor :crossed_fingers:

Aha - sorry, yes this is a second deck, my main one runs on a Lingo - I forgot that was in the signature! Apologies for confusion. This one is a really old LP12 which has gradually coughed and wheezed more and more and has finally grou
nd to a halt!

Thanks for confirming that I shouldn’t try and fit a pulley myself! I’m still not sure whether I can just pop a Premotec 31813 in there without having to change a load of other components.

I’ve checked online and yes it seems to be the replacement motor according to Farnell and others.
Pulley might be a different matter it will be a press fit.

Those Wilmslow speakers have ended my decades of faffing with various Spendor, PMC, home-made or home-modified setups. I think the ATC mids are what really does it - but also all I think the transmission line is the solution to another problem - previous speakers I used were fussy about placing, leaving dead spots and bass traps… these sound the same wherever you are in the room, and I often jump out of my skin when listening to the radio and a new voice comes into the studio! I’ve worked with ATCs in studios most of my life and I just thought those mids would finally do the job I was after, and they haven’t disappointed at all, and them being passive and single-amped makes them a bit more mellow than some of the brutal studio setups I’ve worked with. Only down-side, they’re the size of small wardrobes!

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That’s wonderful, thank you. I’m not into tinkering so the easiest swap is the preferred option!

PS there are several options - I don’t quite understand what’s what - McLennan, Premotec, Allied Motion… if they’re all roughly equivalent, I’ll just go for anything with a pulley already fitted.

Another thing which I find confusing (sorry if I’m being dim!) - the existing motor says “50Hz - 60Hz”, some motors are labelled 50Hz and some 60Hz… I don’t really understand how one motor can be both! Presumably I need 50Hz as that’s my local supply?

You’ve got it yes 50hz
There have been a number of different makes of motor over the years but Premotec seems to be the most common.
It might even be worthwhile contacting some Linn dealers they might have a good quality pre loved option.
The pulley is a linn item press fitted.

Thanks - for the info. Sounds like you have your end game speakers :+1:

I wouldn’t leave it open, keeping it opened is not optimal as it leaves it unsupported, causing the spindle to ride on the bottom bearing sleeve, which is not how the motor was designed to operate. Keep in mind these motors are generic, with the pulley and spindle height being the primary components that differentiates them among manufacturers.

Linn discovered that the original noisy plastic/spring thrust pad, designed to prevent the spindle assembly from riding on the bottom bearing sleeve, ended up causing more issues than it solved. Instead of addressing this problem, they opted for a quick fix by discarding the inexpensive thrust pad assembly. It remains puzzling why they only recommended this “fix” for Lingos, as the underlying issue persists regardless of the power supply being used.

I would rather recommend the SRM-Tech Turntable Motor Thrust Bearing:
144608334288_ml

This solution allows the spindle assembly to glide between the upper and lower sleeve bearings by providing support through a high-quality stainless steel ball bearing acting as a thrust pad. By reintroducing a proper thrust pad this upgrade is more inline with the original design of the motor and will result in much quieter motor operation compared to either stock or Linn “modified”.

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Easy. Pre-Valhalla, when the motor ran directly off the mains, different diameter pulleys were used for 50Hz and 60Hz.

From Valhalla onwards, a clean 50Hz is generated, from whatever mains goes in (50 or 60Hz). So the 50Hz pulley is then universal.

Simple really…

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Thanks for all the replies - actually I’m giving up on the existing motor, I’m getting a S/H replacement from a dealer I know well, he’s doing an upgrade for someone and it will be available in a week or two.

Thanks for the “50Hz-60Hz” explanation!

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That’s why I said this. :+1:t2:

Exactly - I went with your advice!

Also cos said dealer will have one available, by chance.

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I wouldn’t discount the power supply. I had identical problem, solved by replacing the power supply.

Have you checked the 22uf capacitor, that’s the cap that starts the motor spinning.

That was my first thought, though mostly because that was the cheapest thing to check first! I thought by the time I’ve taken caps out to check them, I might as well replace them. So they’re all new.

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Yes, my motor stopped working a few years ago. I spoke to a very well known dealer who advised me that it was unlikely to be the motor. Very rare that they fail. He was right when he said it would be the power supply. In my case a Lingo 1.

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