The RB-PD2 is a stereo audio profanity delay used for live broadcast programs to prevent the transmission of unwanted or obscene content. It features an automatic audio stretch algorithm that allows building between 2 and 55 (*) seconds of delay during live broadcast while maintaining correct pitch. The delay can also be acquired while playing a pre-selected audio file from a Compact Flash™ memory card. Once the program is finished, the audio stretch algorithm gradually reduces the delay to zero.


The RB-PD2 has balanced analogue and AES/EBU digital audio inputs and outputs on 3-pin XLR connectors and supports sample rates up to 48kHz at 24 bits. It can function as a combined A/D and D/A converter, meaning that analogue inputs can be converted to AES/EBU outputs or vice versa.

The delay can be initiated by pressing the BUILD DELAY button on the front panel. A front panel display shows the amount of delay being built, up to the initially selected value.

There are several ways to ensure that any unwanted content is removed from the audio at the outputs. A COUGH function, activated from a dedicated front panel button, allows locally generated sounds presented at the inputs, such as presenter coughing or equipment switching noise, to be discarded.

The DUMP function, also activated from a front panel button, has 2 different modes. The first DUMP mode removes an already buffered audio section, of a pre-selected duration. The second DUMP mode plays a pre-selected audio file from the Compact Flash™ card. When the file playback is complete, the delay is then equal to the file duration. The DUMP button can be used multiple times to use up the accumulated delay and once used, the unit automatically starts rebuilding the initial delay.

As a last resort, all buffered audio can be removed by holding down the DUMP button which activates the DROP function.

At the end of a radio show when you want to broadcast live, the delay can be gradually reduced by pressing the EXIT DELAY button on the front panel.

A dedicated recording mode allows recording the audio present at the analogue or digital inputs to a linear WAV file on a Compact Flash™ card. Additionally, the card format used is PC readable, allowing easy transfer of pre-recorded linear WAV files from a PC or similar device.

A blue vacuum fluorescent front panel display with rotary control is used to select the various profanity delay parameters, which include start and dump modes, safety period, source (analogue or digital), sample rate and sample width as well as the required delay time. The current delay value, in seconds, is permanently displayed along with the current unit status. Additionally, input peaks can be selected from +12dBu, +18dBu and +24dBu for FSD and two rear panel left and right preset potentiometers allow for modifying the input gain range by ±3dB around the selected peaks. The analogue output gain range can be modified via software from -6dBu to +24dBu output level, ref FSD. The analogue and digital outputs can be muted separately and a front panel Bypass button disables electromechanical relays to bypass the analogue and digital inputs to their outputs. This is also disabled automatically during power failure.

The RB-PD2 has a remote port providing 8 inputs and 6 outputs, all freely assignable. The inputs can be used to trigger any function of the unit such as building delay, activating cough or entering record mode and starting a new recording. The outputs can provide external signalling to indicate when certain events have occurred such as the delay reaching the required value or the outputs being muted. Additionally, the 6 remote outputs can optionally follow 6 of the inputs with the current program delay inserted between the activation on the input and the activation on the output. This can be useful for timed events that need to take into account the delay accumulated by the RB-PD2.

As playback from a Compact Flash™ card can be remotely triggered, the RB-PD2 can also be used at transmitter sites to play an emergency audio file via GPI when silence is detected.

The front panel controls can be locked for situations where remote control is used to operate the unit, or when physical security is required. A red LED indicates when power to the RB-PD2 is active.

* At 32kHz 16bit