For use in live broadcast programs to prevent unwanted or obscene material from being transmitted, this delay unit is intended for insertion in the studio output path. An automatic audio 'stretch' algorithm allows between 2 and 55 seconds of delay to be built up live whilst 'on air', whilst maintaining the correct pitch. Alternatively the delay can be acquired whilst playing a pre-selected audio file on a Compact Flash memory card. Once 'in delay', unwanted material may be removed from the output by several ways, involving the deletion of a number of seconds of the buffered audio signal or substituting an audio file from the memory card. Both balanced analogue and AES/EBU digital audio inputs and outputs are provided.
The unit can act as a combined analogue to digital and digital to analogue converter: Analogue inputs can be output as AES/EBU signals and vice versa.
Housed in a red-anodised aluminium rack-mounting case, the delay is intended to be mounted in a studio or equipment room and operated using the controls on the front panel, or the various remote options. The controls on the front panel can be locked out, in situations where remote control is being used to run the unit, or where physical security is required. Sonifex SCi software, available free of charge as a download from Sonifex, when installed on a suitable PC, provides graphical access to all remote control and configuration options via both RS232 and USB interfaces. Alternatively, commands may be issued from any text-based terminal application.
The front panel is dominated by a vacuum fluorescent display which displays permanently the current delay value, in seconds, and the current status of the unit. An associated rotary selector with integral push-switch is used for selecting the various settings, which include the start delay and dump modes, safe period, source (analogue or digital), sample-rate and sample bit-width as well as the required delay time. Four push buttons offer 'Build Delay', 'Exit Delay', which ramps the delay down to return to real-time output, 'Audio Bypass', which disengages relays to divert both analogue and digital inputs to their outputs and 'Cough', which allows locally generated sounds being presented at the inputs, such as the presenter coughing or equipment switching noises, to be discarded. A larger button operates the dump function, which has two different modes. The first removes a section of audio that has already been buffered, by a pre-selected amount. The second mode plays a pre-selected audio file on the memory card inserted in the CF slot, which supports cards up to 2GB. When the file has finished playing, the delay is then equal to the duration of the file. The dump button can be used multiple times to use up the built-up delay and once used, the unit starts to rebuild the original delay time automatically. As a last resort, all the buffered audio can be discarded by pressing and holding the dump button, thus activating the 'Drop' function. A dedicated record mode allows audio presented at either the analogue or digital inputs to be recorded to a linear WAV file on the memory card. Files may be transferred to and from the card using a PC.
The rear panel has two pairs of XLR connectors for balanced line-level analogue inputs and outputs. The inputs have adjacent trimmers of level. A further pair of XLRs are used for the AES/EBU digital input and output. A 15-pin male D-Sub connector provides external control; eight inputs and six outputs are assignable freely. The inputs can be used to trigger any of the unit’s functions such as build delay, activate cough or enter record mode and start a new recording. The outputs can provide external signaling to indicate when certain events have occurred such as the delay reaching the required value or the outputs being muted. A 9-pin male D-Sub connector provides an RS232 serial port. Power is connected by a filtered IEC inlet, with adjacent fuse.
Sampling frequency: 32kHz, 44.1kHz or 48kHz. Sample width: 16-bit or 24-bit. Minimum delay: 2 seconds. Maximum delay: 55/27.5 seconds at 16/24 bits, 32kHz; 40/20 seconds at 16/24 bits, 44.1kHz; 37/18.5 seconds at 16/24 bits, 48 kHz.
Analogue audio inputs: +28dBu maximum, 10kohms. Analogue and digital level: +12dBu / +18dBu / +24dBu for FSD. Analogue trimmers: +/-3dB. Noise: Better than -101dBFS RMS, A-weighted, 24bit. Dynamic range: Better than 110dB. Distortion: Better than 96dB THD plus noise, 1kHz. Analogue audio outputs: +24dBu maximum, 50 ohms. Dynamic range: 100dB minimum. Gain range: -6dBu to +24dBu output level, ref FSD. Power source: 85-264V AC, 47-63Hz, 60/30W peak/average. Dimensions: 480 x 158 x 43 (w x d x h)mm. 1U rack mounting. Weight: 1.7kg.
Included accessories: Handbook, AC power cordset with plug.
Optional accessories: Compact Flash memory card up to 2GB capacity, PIO type 4 or higher.