Just a tiny correction: Of the two DIN jacks, only one is for audio in/out, the one with five pins. The six pin jack serves either as input for an external power supply (7.5 V / 250 mA) or as a connector to the on/off switch of the microphone that came along with (most of?) the recorders. BTW, newer (Philips) models also had a DIN speaker jack.
Just a tiny correction: Of the two DIN jacks, only one is for audio in/out, the one with five pins. The six pin jack serves either as input for an external power supply (7.5 V / 250 mA) or as a connector to the on/off switch of the microphone that came along with (most of?) the recorders. BTW, newer (Philips) models also had a DIN speaker jack.