Dual Mic / Line Preamplifier

Ideal Use Cases

The RDL RU-MLA2 is a two-channel audio preamplifier for systems that need configurable microphone or line-level signal handling. Channels A and B can be used as a stereo pair or as two independent mono channels. This makes the unit suitable for applications involving two microphones, two line-level sources, or a combination of mic and line signals. Front-panel XLR connections support direct equipment access, while rear detachable terminal blocks provide an alternative connection point. Each output can also be switched between mic and line level, allowing the preamplifier to interface with equipment requiring either output format.

Why Choose This Model

The RU-MLA2 combines two independently adjustable channels with selectable input and output operating levels. Mic or line input selection is available from the rear panel, while switch-selectable mic gain accommodates different microphone signal levels. Phantom power is also switch-selectable. A dedicated gain trim control for each channel is located on the front panel, allowing channels A and B to be adjusted separately. Both inputs and outputs are available through front-panel XLR jacks and rear detachable terminal blocks. This connection layout gives users a choice between accessible front connections and rear wiring without requiring separate interface hardware.

Installation and Integration

Each of the two inputs is available on a front-panel XLR connector and a rear detachable terminal block. The two outputs use the same connector arrangement. Input mic or line selection is located on the rear panel, and each output is switch-selectable for mic or line operation. The unit requires a ground-referenced 24 Vdc power source rated for 80 mA. A power supply is not included. The recommended supply is the PS-24AS for the USA or the PS-24AX for international use. The specified ambient operating range is 0° C to 55° C. Front-panel gain trims keep routine channel-level adjustment accessible after the remaining connections and operating selections have been made.

Performance Highlights

The published input levels are specified for a +4 dBu output. In low-gain mic mode, the stated range is 48 dBu to -3 dBu; in high-gain mic mode, it is -65 dBu to -20 dBu. The stated line-input range is 15 dBu to +28 dBu. The two outputs have a balanced impedance of 150 Ω. THD+N is specified at less than 0.1% in mic operation and less than 0.005% in line operation. Common-mode rejection is greater than 60 dB for mic signals and greater than 50 dB for line signals. The RU-MLA2 also provides more than 20 dB of headroom above a +4 dBu line output. These published values distinguish the performance characteristics of its mic and line operating modes.

What Makes It Different

The RU-MLA2 places input type, microphone gain, phantom power, output level, and channel gain within one two-channel preamplifier. Its channels can function together for stereo operation or separately for dual-mono use. The availability of both XLR and detachable terminal-block connections on the input and output sides further expands how each channel can be connected. Unlike a preamplifier limited to a single signal type, this model supports selectable mic or line inputs and independently selectable mic or line outputs. The front-panel gain trims provide one adjustment for each channel rather than a shared level control.

Final Assessment

The RDL RU-MLA2 is a focused choice for two-channel audio systems requiring mic and line flexibility. Its combination of selectable operating levels, low- and high-gain microphone ranges, phantom power, balanced 150 Ω outputs, and separate gain trims provides detailed control over channels A and B. Front XLR connectors serve accessible connections, while rear detachable terminal blocks support an alternate wiring arrangement. With stereo or dual-mono operation and published performance specifications for both mic and line modes, the RU-MLA2 consolidates several signal-interface functions into one preamplifier.