There is a built-in talkback microphone with functions as follows:
- TB to Foldback sends talkback signal to the foldback outputs.
- TB to SLS sends talkback to the studio loudspeakers.
- Slate cuts all loudspeakers and sends talkback to multitrack outputs 1-48, main outputs, foldback sends and studio loudspeakers. A 30 Hz tone is mixed in to allow rapid finding of slate announcements recorded on analog tape machines.
- Two 'listen mics' can be installed in the studio to monitor audio activity other than via the recording microphones.
- Red Light allows a studio red light to be switched on automatically when the multitrack is put in record mode.
- There is an additional cue light with button activation.
- Ext T/B provides an additional talkback destination, plugable from the patchbay.
- Auto Cue allows the Talkback and Listen Mic switches to be latched on for continuous communication between the control and studio, but only when the multitrack is in Stop or Wind mode.
- The Oscillator sends tone to the multitrack and main outputs. The main use of this is to record tones of a range of frequencies at the same level to an analog multitrack. When the tape is played back, the playback machine can be aligned for a flat frequency response. Digital recordings also use tone, but just to set a reference level. SSL recommend switching the oscillator off when not in use to prevent tone leaking into other signal paths.