Sony PS-LX500 speed adjust, How?

[Fast one]

I downloaded the service manual but it doesn't explain how to adjust the turntable speed. Does anyone know the procedure and what trimmers are for doing this? There are two adjustments for gain (RV101 and RV102) and two adjustments for offset (RV103 and RV102) with a lot of voltages in red shown on the schematic. Nothing is explained on how to adjust speed.

[Coffee Phil]

Hi Fast One,

I looked in the library on this site. There is just an owners manual. No service manual. It has no mention of speed adjustment or if it is quartz locked. Those adjustments may be for the arm servo. Can you give a link to your manual. That may give some insight.

Phil

[Fast one]

I used the one for the PS-LX510, after looking through it again there is a a page with a complicated procedure that appears to be for speed adjustments. An ocilloscope, voltmeter, and dc power supply are used to set a 4 volt PP clean waveform and that seems to provide a correct turntable speed or speeds. It couldn't be more complicated or vague.

[fscl]

Searched VE for "Sony" "direct" "drive" "FG" "servo" "control" and returned the LX500 (no service manual) and the Sony PS-FL77 (which has a service manual)

Download the service manual:

https://www.vinylengine.com/library/Sony/ps-fl77.shtml

You are correct that RV-101 and RV-102 control the 45RPM and 33RPM speeds respectively. Page 17 of 41 shows how to adjust to the correct speed using a frequency counter. In lieu of one, carefully free the servo control board (don't know if the pots are facing downward, if so, you may be able to adjust with the back cover off and with the turntable on soup cans), shoot the potentiometers with contact cleaner and adjust speeds using a strobe disc downloadable from VE.

Good luck and welcome to VE...... :)

Fred