Two-channel limiters, useful in radio and TV news-rooms, control rooms and other locations where assistance with level control is required, for protection of mixer inputs and to prevent distortion. Models are available with line inputs and now with microphone/line inputs.
All models are housed in red-anodised aluminium cases with apertures for fixing screws, they can be attached to any flat surface, or rack-mounted from the front with the standard front panels, or in reverse, with the rear panel facing out of the rack, using accessory panels.
RB-ML2 - Two channels - Microphone/Line
With inputs and outputs that can be switched to microphone or line signal level, the RB-ML2 is particularly useful for news gathering as the input to PC workstations. It can operate in stereo or dual mono modes.
The front panel has a power indicator which also acts as a limit indicator. The rear has two electronically balanced 3-pin XLR inputs; each of these has a push-button to select microphone or line input sensitivity, and a recessed level control accessed by screwdriver. Four miniature switches allow the selection of LF cut and phantom power for these inputs. There are two electronically-balanced 3-pin XLR output connectors, each of which also has a microphone/line level switch. The outputs also have gain and limit level control associated with each. A final switch selects stereo or dual mono working. Stereo limiting operates by limiting both left and right outputs if either left or right input needs to be limited. Dual mono limiting operates by limiting left and right signals individually; the RB-ML2 may be used as two separate mono mic/line limiters.
Inputs: -6dBu/+28dBu maximum mic/line, 20kohms. Phantom power: +48V. Common mode rejection: 86dB/66dB mic/line. Input gain: +22dB to + 67dB microphone, 0dB line. Response: 20Hz to 20kHz +/-0.1dB. Low frequency filter: 6dB/octave, 125Hz. Distortion: 0.02% THD + noise, 1kHz, +8dBu output. Noise: -70dB, unity gain, +8dBu output. Outputs: -18dBu/+28dBu maximum mic/line, 50 ohms. Output gain:-54dB to -24dB microphone, -8dB to +22dB line, ref 0dBu line input. Limit threshold: -8dBu to +28dBu. Power source: 110-120V or 220-240V AC 6W maximum. Dimensions: 280(w) x 108(d) x 42(h) mm. Weight: 1.1 kg.
Included accessories: Handbook, AC power cordset with plug.
Optional accessories: The RB-RK1 is a 1U panel to rack-mount the device with the connectors inside the rack. The RB-RK2 (1U) rear-panel kit allows the device to be rack-mounted in reverse, with connectors outward.
Essentially this a similar to the RB-ML2, but without the microphone level facilities. Applications are similar to the RB-ML2; the RB-SL2 is often used as the main output limiter in smaller broadcast installations.
The front panel has only the power indicator, which flashes to show limiting. The rear panel has the same features as the RB-ML2, except there are no mic/line, phantom power or LF cut switches, and no microphone gain trimmers.
Inputs: +28dBu maximum, 20kohms. Input Gain: -8dB to +18dB. Common mode rejection: 66dB. Response: 20Hz to 20kHz +/-0.1dB. Distortion: 0.01% THD, 1kHz, +8dBu output, threshold set at +10dBu. Noise: -100dB, unity gain, +8dBu output. Outputs: +28dBu maximum, 50 ohms. Limit threshold: -8dBu to +28dBu. Power source: 110-120V or 220-240V AC 6W maximum. Dimensions: 280(w) x 108(d) x 42(h) mm. Weight: 1.0 kg.
Accessories: As RB-ML2