Technics SL-1200MK2 Pitch Calibration

The AN6682 integrated circuit is the main electronic component responsible for the pitch control circuit. It forms a closed-loop servo that maintains a precise speed. VR301 is the pitch control ±0 % adjustment preset, whilst VR302 is the pitch control gain adjustment preset.

Calibrate VR301

1. For this calibration, you need access to the component side of the drive control circuit board. Before you begin the calibration, you will need to set the main pitch control slider to "0", where the indicator lights up.
2. Connect the frequency counter between test point (TP27) and earth.
3. Adjust VR301 so that the frequency counter reads 262.08 kHz ±0.05 kHz

Calibrate VR302

1. For this calibration, you will require access to the connector CN102 on the Drive Circuit Board. You will need to connect your probes to terminals 5 and 6 of this connector.
2. On the Pitch Control Circuit Board adjust VR302 so that your multimeter (set to read resistance) reads 2.7 kΩ ±0.1 kΩ

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