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Pink Triangle PT2 vibration

robbyd

pfm Member
Hi -

I won a PT2 from eBay a while back, good price, and have only just got round to firing it up..

there's a vibration that can be felt through the arm tube... At worst, depending on suspension setting, it can make the whole system oscillate into a bouncing by itself!!. Feels like 50hz mechanical.

I have tried a new belt. My instinct is that it is a mechanical issue, though I understand if components in the PSU start going, the speed will be affected (well of coursed they will) - but this feels like the motor itself. If I apply a bit if force to the motor body as it's running, the vibration decreases.

Any thoughts?

Just wondering if there's anyone here with a PT2 who'd be willing to try out my original PSU - if you get the same issues, then it's the PSU...

thanks!
 
One tip.. make sure that the arm cable isn't impeding the suspension bounce. This would cause the suspension to visibly shake the arm/platter. Thick arm cables are tricky to 'dress' for these decks.
Truepoint change all the suspension springs & components when they do a service on the old Pinks, at this point in time they may be past their best. Good luck!
 
Thanks - def not arm cable...

truepoint already offered me a dc motor & controller but I'd rather not be spending that sort of money on this particular deck.

I'm wondering if the belt is riding up on the underside of the pulley flange - but there's no adjustment for that...
 
May have got somewhere with this...

removed belt and spun platter by hand - a really bad vibration can be felt when holding the arm tube, so I'd say at this time that the main bearing is shot...

calling true-point tomorrow...
 
Is the bearing spindle firm? (I.e it doesn't move). I did come across one which was loose in it's base due to an accident. Otherwise.. the metal parts are usually ok, it is the ceramic jewel on top of the bearing which is the most likely to get damaged/chipped. Can you see anything amiss visually? My 30yr old Anniversary was recently with Truepoint and there was a small chip in mine which they rectified.
 
Yes the spindle is firm - there is lateral play as you lower it down, until the jewel engages. It feels fine until the platter is spun. With motor off and no belt, I can't think of any other cause...
 
If it wasn't packed correctly when it was sent to you then the jewel could have been damaged
Or it might have been like this for a while and the eBay seller was hoping you wouldn't notice or would take on the repair yourself!!
 
Yes - the risks of eBay... I did collect in person and it travelled with platter removed.

The bearing is with TruePoint at the moment, being refurbished... so hopefully back soon as good as new...
 
There is no jewel in any PT bearing - just advertising spiel to impress the gullible. The bearings are a steel ball bearing running in a PCA (poly-crystalline alumina - a very ordinary, very common, very cheap and cheerful industrial ceramic) cup.
For transport, PT decks MUST NOT have the platter installed and the suspension must be locked with the bolt through the top plate.

You can isnspect the ball easily enough using a low power lens. If the bearing is original, the ceramic is is in the female part of the bearing and is essentially impossible to inspect properly as it is beyond the focal length of any magnifier that is of real use - you'd need a boroscope.

If the rumble is reasonably accurately 50Hz, it can't be the bearing, unless you play lots of 45's.

The simplest motor rehash is to use the motor and controller from a Technics? Sony? deck that you can pick up for not very much money - plenty of details over on Vinyl Engine, including which model to use as donor. If you want one of the motors/controllers, drop me a PM as I bought a wrecked deck to provide a spare for my PT1, just in case, which I sold a while back. The replacement would be DC.

Truepoint are good but total rip-off merchants.
 
The simplest motor rehash is to use the motor and controller from a Technics? Sony? deck that you can pick up for not very much money - plenty of details over on Vinyl Engine, including which model to use as donor. If you want one of the motors/controllers, drop me a PM as I bought a wrecked deck to provide a spare for my PT1, just in case, which I sold a while back. The replacement would be DC.

I certainly know of 2 LPT that have been modded in this way and it works well ,albeit a little slower on startup.
 
I think that someone may have used something like WD40 to lubricate the bearing rather than it actually being faulty.

I've come across this many times in turntables and cd players which use a sled drive, geared and magnetic.

I can't offer a cure for this particular turntable as I have no in-depth knowledge of it but if the bearing is firm and the platter turns easily but you're getting a 'shudder' it's more than likely someone has contaminated the sleeve by using the wrong lubricant

Clean it and get the correct lubricant is the best advice for all mechanical problems.....unless it's broken.

Happy days.

:D
 


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