PS-X800 Buzzing Sound

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adamz
Posts: 2
Joined: 26 Apr 2015 08:00

PS-X800 Buzzing Sound

Post by adamz » 28 Dec 2017 11:46

Hello all!

I have a Sony PS-X800 (45w, 110v US model) that I have been using with a 200w step down transformer in Australia. When I first got the table about 6 months ago it required replacement of tonearm belts (I succeeded in this "micro-surgery" and got the table working again). Everything was working fine, I even fitted the table with a Sony XL 55 Pro cartridge (I have the auxiliary weights). Then, about 2 months ago, the table developed a low-level, rhythmic electronic humming/buzzing sound when spinning coming from where the motor is. Agh! I can still listen to records, but this annoying sound is audible during quiet segments...

At 45rpm, the sound speeds up. I have noticed that when I "help" the platter spin a tiny bit the sound goes away (when I take my finger off, it instantly returns). Any ideas? I have a spare PS-X800 (Japanese model) that has a bad bio-arm so I could replace other parts if required. I checked the platter/magnet on the motor - all seem fine. Any ideas? I tried oiling the spindle to no effect so I do not think it's a mechanical issue?

Best,

Adam

langer

Re: PS-X800 Buzzing Sound

Post by langer » 03 Mar 2018 23:58

Hello from Germany,

the voltage through the upstream transformer is correctly 110V or maybe too low on the PS-X800?
Otherwise the secondary voltages in the player (after its own transformer) could be too low for the motor control.

If the tension should be right:

Is the acceleration of the plate from standstill slower than it used to be?
Does the plate have less power than it used to?

It could be (that would match the buzzing sound) that the motor winding lacks a half-wave through the drive (similar to a push-pull power amp),
or half-wave is only partially / unclean,
or that the sine wave is jagged rather than uniform.

This can be checked as well as the offset and gain of the engine control.
The signal shape to the motor windings, as they should be optimal, is described in the Service Manual page 17 and 18.

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