Manually powering up the SP 20
Though the SP 20 will normally power itself up automatically when connected by detecting a bias voltage on the microphone terminal, there are certain conditions where this may not occur. This includes using the SP to play music from an MP3 player or another device where the bias voltage from the microphone terminal is either non-existent or switched off to conserve battery.
The SP 20 can be forced to power up by pressing and holding both the green and red buttons for 5 seconds.
Please note that the SP 20 will not power down automatically after is has been switched on manually.