The speed of my Sony PS-X800 is going up and down every turn and while it was seen by a technician and also buying an another platter thinking that the magnetic strip went bad ,it is still the same at this point. I know the motor grease shouldn't be touched for the life of the unit as it's mentioned in the manual but maybe after all these years the lube starts to harden so the platter wouldn't freely spin? Have anyone changed the lube for this turntable? I'm just asking because it seems a bit complicated and I don't want to do something stupid.
Replacing the grease/oil in the motor shaft for a Sony PS-X800?
- Thread starter lucius72
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KentTeffeteller
Gimpus Stereophilus!
Sealed bearing, lubed for "Life".
Roman68
Active Member
Hello. I would still try to change the engine lube on yours. On my Sony ps212, I changed the lubricant. I think so, even though the user manual says that the oil does not need to be changed, but the developers did not think that people would use these turntables for 30-40 years. Changing the oil itself is not a difficult process, carefully remove the engine rotor, wipe the surfaces with alcohol, do not scratch anything, drop a few drops of spindle oil into the engine glass, and a few drops onto the rotor to get a thin layer on it. And slowly insert the rotor into the glass, scrolling it so that the air comes out. That's it, oil change done.
@KentTeffeteller is correct. Those bearings were supposed to be lubed for life. If you really want to investigate further, I would buy one with a dead motor and try taking it apart first. May not have to be the same X800 model but experiment on a non running motor before you try to take yours apart and find out it does not go back together.
flavio81
Turntable technician
There is a problem with this reasoning, and the problem is that you are trying to change or replace things without having a clear idea of the cause.
I can safely tell you that if you are experiencing speed instability the bearing is a very unlikely cause unless there is significant noise when it turns and significant friction. Those sony motors are very torquey.
Most probably there is an electronic problem. I have a sort-of guide that a turntable technician can follow to troubleshoot, here:
https://audiokarma.org/forums/index...rive-bsl-motor-works-troubleshooting.1021427/
Most probably your TT will require cleaning of all potentiometers, changing of some capacitors, maybe some power transistor is faulty as well. And no doubt, realignemnt as per in the link i've sent here.
Roman68
Active Member
if the speed changes with strict periodicity, then the problem is more of a mechanical origin. Capacitors or potentiometers do not give such an effect; if they fail, the speed changes will be chaotic, but regardless of the degree of rotation of the rotor. Of course, cleaning variable resistors, and possibly replacing capacitors, will not hurt, provided that there is experience and skill.
flavio81
Turntable technician
Your argument is not considering that this is a Direct Drive turntable where the motor torque is very strong and thus the first suspect of speed variations is the motor (coil) force itself. In other words, the speed control system. Moreover if the bearing had friction (unless very obvious, noisy friction), a control system in good health would totally compensate for it. So again, i'm suspecting on the electronics in #1.
The speed control on the PS-X800 (and other sony TTs) depends on comparing the readings from a magnetic imprint on the platter by a magnetic head (usually 300Hz frequency) and comparing this with a reference oscillator (usually quartz crystal) using a sort-of phase locked loop (PLL), which then controls a DC voltage which directly controls turmtable speed. This is all mentioned on the link I gave above.
If this final DC voltage isn't steady then you will have speed changes with or without all kinds periodicity, again of a fully electronic cause, since this voltage directly sets the instantaneous speed.
This can be due to many things, for example for the PLL to work correctly there is a pulse adjustment that depends on a potentiometer. Wrong pulse adjustment, then the TT won't react to speed variations with the correct quickness. This is only one of the things that can go wrong.
Power supply unsteadiness/ripple/variation will directly impact (among MANY other things) the DC voltage input to the Hall elements and this will directly change driving coils' power (voltage amplitude) which if not properly compensated by the speed control circuit will also result on unsteady rotation of all sorts.
A faulty power transistor (and i don't just mean "transistors of the power supply", i mean all power transistors and more particularly the ones that drive the motor coils, 4 in total) will cause a lot of problems. These 4 transistors are directly connected to +V and -V power supply, so shorted or faulty transistors will directly break havoc with two of the supply rails and cause all, all sorts of trouble.
Really there are many, many electronic and electrical things that can go wrong compared to mechanical things. Not just "capacitors and potentiometers", this was just a partial list if you read my post above.
I do agree that cleaning and reoiling the bearing is so easy to do that it's a no-brainer to try this. But I am suspecting this won't solve the problems.
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I had inconsistent speed issue with my x600, and the cause were oxidized pots on the motor board (pots for gain and offset). I replaced all of them and solved the problem, so ignore the comments from people that never worked on these tables.
Be aware that an oscilloscope is a must for pretty much any adjustment on these tables.
For the magnetic strip - you can measure the output from the pickup with a multimeter and check if you get a correct reading. Of course if you want to see the waveform of the pickup you again need a scope.
Be aware that an oscilloscope is a must for pretty much any adjustment on these tables.
For the magnetic strip - you can measure the output from the pickup with a multimeter and check if you get a correct reading. Of course if you want to see the waveform of the pickup you again need a scope.
Roman68
Active Member
it's all clear. But in this case, I would start the repair with a simple one, inspect the motor bearing, lubricate, replace the capacitors, clean the variable resistors, this is all that can be done without using an oscilloscope and interfering with logic. After replacing the capacitors, it makes sense to measure the voltages at the control points, it may become clear in which circuit to dig. The Hall sensor may fail, there may be problems with the engine drivers, that's all. If there is a skill, then take waveforms, adjust modes, offset, etc. Alternatively, you can measure the resistance of the motor coils to rule out the cause in the motor itself. I would still start the repair with the elementary.
flavio81
Turntable technician
x1000 !! I bought a 2nd oscilloscope recently just for servicing DD tables...
Just by cleaning those trim pots you will interfere with logic - because you cannot be certain that all of them can equally be cleaned. And by doing that without a scope you might fool yourself to think they are ok since the problem is still there.
Replacing capacitors just for the sake of it won't solve anything and might introduce even more confusion, I would just desolder and measure them, but in my experience they measure to spec better than new ones.
If there would be a failed motor coil, the platter would not be able to start spinning on it's own and usually needs a push to start.
Anyway this is the thread I started for my X600: https://audiokarma.org/forums/index.php?threads/sony-ps-x600-speed-issue.1011160/#post-15974824
It might help you, with your issue, which sounds very much like the one I had.