Once Analog Posted September 19, 2013 Share Posted September 19, 2013 Hmm, 9 hours running time and both 33/45RPM still stable, no fluctuation? Vince 1 Link to comment Share on other sites More sharing options...
Upfront Posted September 19, 2013 Share Posted September 19, 2013 Nice work mate. Can't believe that may have been all it was. Link to comment Share on other sites More sharing options...
andyr Posted September 19, 2013 Share Posted September 19, 2013 Well done. maybe you need to get some whale oil for the bearing? Andy Link to comment Share on other sites More sharing options...
soundfan Posted September 19, 2013 Share Posted September 19, 2013 Nice work mate. Can't believe that may have been all it was. Have I missed something here? I thought Vince was posting that he feels he can eliminate the bearing being the problem. Tell me more. Link to comment Share on other sites More sharing options...
Once Analog Posted September 19, 2013 Share Posted September 19, 2013 Have I missed something here? I thought Vince was posting that he feels he can eliminate the bearing being the problem. Tell me more. Stay awake and learn, the fun is just starting! Vince Link to comment Share on other sites More sharing options...
Upfront Posted September 19, 2013 Share Posted September 19, 2013 But we can't see the fun... There's no pictures!!!! Link to comment Share on other sites More sharing options...
lovetube Posted September 19, 2013 Share Posted September 19, 2013 Stay awake and learn, the fun is just starting! Vince Exactly Vince. I still don't believe the bearing was causing the problem . but I'm all ears /eyes open . let's wait for your finding. regards Duc Link to comment Share on other sites More sharing options...
unclemack Posted September 19, 2013 Author Share Posted September 19, 2013 So far it's great news but the Luxman has tricked others including me in the past...Just when you think you have it licked..BAM! it starts speeding up again. Time will tell. In the meantime, here's some pix courtesy of the man himself... Cheers M 1 Link to comment Share on other sites More sharing options...
Once Analog Posted September 19, 2013 Share Posted September 19, 2013 I would disasemble the bearing completely , clean it and check for any falt specially the ball bearing if there is one , depend on how the bearing clearance design to choose the oil viscosity . synthetic oil should be good . Lovetube Hi Duc, Are you contradicting yourself? Vince Link to comment Share on other sites More sharing options...
lovetube Posted September 19, 2013 Share Posted September 19, 2013 Hi Duc, Are you contradicting yourself? Vince hahahaha. Vince. cleaning/ servicing the bearing for this table age is a good thing's and is a piece of mind but as I said earlier it will not be the bearing that cause the speeds to go yo yo . as you discover the bearing tolerance is super on this deck . dirty bearing won't cause the problem it has . i have due with lot of Japanese deck of this age and speed issue always been electronics . regards Duc Link to comment Share on other sites More sharing options...
Once Analog Posted September 19, 2013 Share Posted September 19, 2013 [quote name="lovetube" post="954200" i have due with lot of Japanese deck of this age and speed issue always been electronic a Duc Hi Duc, Me too, but have learnt every road is a different story. This one seems to be on track! Vince Link to comment Share on other sites More sharing options...
andyr Posted September 19, 2013 Share Posted September 19, 2013 Aah, Vince, Duc ... belt drive TTs like the LP12 don't have a speed problem! Regards, Andy Link to comment Share on other sites More sharing options...
CraigC Posted September 19, 2013 Share Posted September 19, 2013 Great work Vince. Link to comment Share on other sites More sharing options...
Once Analog Posted September 19, 2013 Share Posted September 19, 2013 Great work Vince. Hi CJCC67, To your credit as well. Vince Link to comment Share on other sites More sharing options...
Jake Posted September 19, 2013 Share Posted September 19, 2013 I thought the bearing was "not part of the problem". How can one be confident of success yet? Did I miss something? Still reckon the motor is dodgy myself. Link to comment Share on other sites More sharing options...
lovetube Posted September 19, 2013 Share Posted September 19, 2013 Aah, Vince, Duc ... belt drive TTs like the LP12 don't have a speed problem! Regards, Andy can't be better than that Andy . Vince. I hope that is what it is and you have solved it . regards Duc Link to comment Share on other sites More sharing options...
unclemack Posted September 19, 2013 Author Share Posted September 19, 2013 Aah, Vince, Duc ... belt drive TTs like the LP12 don't have a speed problem! Regards, Andy But not belt drives like the Luxman? Cheers M Link to comment Share on other sites More sharing options...
andyr Posted September 19, 2013 Share Posted September 19, 2013 But not belt drives like the Luxman? Cheers M Aah, your Luxman is a belt drive, too, UM? I had assumed, being a well-thought Japanese TT, it must be DD. Regards, Andy Link to comment Share on other sites More sharing options...
unclemack Posted September 19, 2013 Author Share Posted September 19, 2013 Aah, your Luxman is a belt drive, too, UM? I had assumed, being a well-thought Japanese TT, it must be DD. Regards, Andy Ha ha.... Link to comment Share on other sites More sharing options...
andyr Posted September 19, 2013 Share Posted September 19, 2013 I thought the bearing was "not part of the problem". How can one be confident of success yet? Did I miss something? Still reckon the motor is dodgy myself. Yes, I think you "missed something", Jake! Stuart fixed the "motor problem". The drive IC still ran away and the speed increased. He posted that he could get this effect to happen, simply by heating up the IC with a hair dryer. That says to me that something was causing the drive IC to work overtime, so it got hot. It makes sense to me that bearing friction could have caused this - the speed was slowing ... so the drive IC was working overtime to increase speed ... so it got hot. Remove the friction ... and the drive IC doesn't have to get hot ... so the speed remains constant. Why the friction - it would seem old, dirty oil? Regards, Andy Link to comment Share on other sites More sharing options...
Jake Posted September 19, 2013 Share Posted September 19, 2013 I thought the bearing was "not part of the problem". How can one be confident of success yet? Did I miss something? Still reckon the motor is dodgy myself. Yes, I think you "missed something", Jake! Stuart fixed the "motor problem". The drive IC still ran away and the speed increased. He posted that he could get this effect to happen, simply by heating up the IC with a hair dryer. That says to me that something was causing the drive IC to work overtime, so it got hot. It makes sense to me that bearing friction could have caused this - the speed was slowing ... so the drive IC was working overtime to increase speed ... so it got hot. Remove the friction ... and the drive IC doesn't have to get hot ... so the speed remains constant. Why the friction - it would seem old, dirty oil? Regards, Andy Yes, I read all that. But initial inspection of bearing showed no problem. But fault cannot be replicated now, so despite bearing being ok, everyone celebrating. Still think I missed something. Link to comment Share on other sites More sharing options...
andyr Posted September 19, 2013 Share Posted September 19, 2013 (edited) Yes, I read all that. But initial inspection of bearing showed no problem. But fault cannot be replicated now, so despite bearing being ok, everyone celebrating. Still think I missed something. As you say, initial inspection of the mechanical wear on the bearing showed no problem. But I could imagine that dirty oil would have a negative effect - hindering the smooth rotation and so causing the drive IC to have to work harder. Regards, Andy Edited September 19, 2013 by andyr Link to comment Share on other sites More sharing options...
Jake Posted September 19, 2013 Share Posted September 19, 2013 Yes, I read all that. But initial inspection of bearing showed no problem. But fault cannot be replicated now, so despite bearing being ok, everyone celebrating. Still think I missed something. As you say, initial inspection of the mechanical wear on the bearing showed no problem. But I could imagine that dirty oil would have a negative effect - hindering the smooth rotation and so causing the drive IC to have to work harder. Regards, Andy Well, that must be some intolerant IC then. Link to comment Share on other sites More sharing options...
Once Analog Posted September 19, 2013 Share Posted September 19, 2013 (edited) Some thoughts on turntable speed control. Turntables driven by a DC motor usually incorporate a closed loop feedback control system. The design parameters of the controller allow for a range of variables within the motor, pulley, belt, platter and bearing system. If any of these variables e.g. bearing friction, exceeds the expected parameters then the control system may not be able to maintain stability and may even enter a chaotic state. The extent and period of the random variations depends on the type and gain of the feedback. Bearing friction is not an obvious or intuitive cause of erratic speed but should always be considered in diagnosing problems. Removing all traces of old, contaminated lubricants, thoroughly cleaning bearing surfaces and replacing the lubricants with high quality products can work miracles with your turntable speed control and improve the sound as a bonus. Best to all, Vince Edited September 19, 2013 by Once Analog Link to comment Share on other sites More sharing options...
Telecine Posted September 19, 2013 Share Posted September 19, 2013 Great work so far Vince but I an sticking with my theory which means that you still will have an electronic issue to deal with ; ) Link to comment Share on other sites More sharing options...
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