The front and lower panels are engraved the detailing shows that the Lat/Vert markings have been removed and replaced by a 'Stereo Link' switch. The two coloured lights on the lower service panel indicate Normal and Hot operating temperature. An on-board temperature sensor monitors your equipment and displays a simple electronic traffic light system that warns the user on the lower panel that the unit is becoming hot +60 deg. Of course your tube equipment will work shortly after switch on but as with all electronic tube equipment there is a nominal 'warm-up' period of about 15/20 minuites whilst your equipment stablizes for optimum working. A 1U rack mounted fan unit can be provided.
As you can see the rear of the unit looks very much like the original Fairchild 670, this production unit shows clearly the power supply section on the right and the fully balanced audio section IN & OUT on the left.