The RM-MP12A is intended for monitoring the level of up to twelve separate mono inputs, each of which can be individually adjusted to suit unbalanced consumer, balanced professional, 8 ohm speaker line or 25V, 70V or 100V speaker lines. An interlocked selection system chooses the input or inputs to be monitored, which are then displayed on a meter and can be monitored on internal or external loudspeakers and/or headphones. Both variable and fixed-level line-level outputs are available. The device is powered from 24V DC, and mounts into a single unit of 19-inch rack space.
The front panel has an LED level meter , styled to look like a conventional VU meter, with -18, -10, -8, -6, -4.5, -3, -2, -1, 0, +1.5, +3, +6, +10, +14, +18 scale markings. Twelve keyboard-style momentary pushbuttons are used to select the input to be monitored, each with a corresponding LED indicator to show which source is selected. Above each switch there is a variable intensity LED to show audio level at the input, minimum intensity is at -15dB, maximum intensity is at 0dB. In the mixing mode, each button alternately selects and deselects an audio source; multiple sources may be selected at the same time. In the interlocking mode, pressing a button selects the corresponding source and deselects all other sources. If the button for an active source is pushed, all audio sources are turned off until the next source selection is made. To the right of the a loudspeaker grille, there is a 6.35mm stereo headphone socket and a volume control which controls the audio level of the headphone socket, the internal speaker, the external speaker output and the variable line-level (+4dBu) rear-panel output.
The rear panel has twelve sets of detachable terminal-block for the inputs. These may be wired balanced or unbalanced. Each has an associated pair of switches to set the input type and a rotary control to set the gain of the input to adjust the level to suit the normal level of programme. Further terminal-blocks provide the fixed, +4dBu line-level output, the variable line-level output, which is controlled by the volume control on the front panel, the loudspeaker output, speaker loop-in, and the 24V DC power input. A coaxial input is also provided for the power. Two switches set the selection mode to interlocked or mixing and the internal or external speaker to mute when a headphone jack is inserted.
Inputs: -11dBu to +9dBu for +4dBu nominal input, 25V, 70.7V, 100V, each set by rear-panel switches, calibrated with gain trim set fully counter-clockwise. CMRR: 75dB, 50-120Hz. Headroom: 18 dB above calibrated input level. Gain: -5dB to 15dB for +4dBu input; 0-20dB, adjustable for speaker-level input, 25-turn trim potentiometer. Response: 10Hz to 20kHz +/-0.25dB. Distortion: 0.01% THD+N, 20Hz-20kHz. Noise: -80dB, channel on, referred to +4dBu. Crosstalk: -80dB, 10Hz- 20kHz, channel to channel. Channel-off attenuation: 80dB, 10Hz to 20kHz. Outputs: +4dBu fixed level, balanced or unbalanced, 150 ohms; +4dBu maximum variable level, balanced, controlled by volume knob, 150 ohms; 4.5W RMS, 8 ohms external speaker; 100mW headphones. Power source: 24-33V DC, 700mA, ground-referenced. Dimensions: 1U rack-mounting, 136mm deep.
Included accessories: Manual. No power supply is included.
Optional accessories: Power adapter, 24V, see RDL Power Supplies.