GPO PR50 Mode D'emploi page 13

Headphone Out
Headphones can be connected using the Headphone jack.
Pitch Adjustment
When the Pitch knob is centred on the middle line, the record player
plays at normal speed. When the LP speed is slower than expected,
you can turn right to adjust the speed. When the LP speed is faster
than expected, you can turn left to adjust the speed.
13