Mic/Line Bi-Directional Network Interface-4 Switchable Mic or Line Inputs, Dante Input-4 Balanced Line Outputs, Dante Output

The RDL RU-MLB4 is a professional 4×4 audio interface for bidirectional conversion between analog audio and a Dante network. It converts four Dante channels to balanced line-level outputs while sending four local audio sources to Dante channels. Each analog input is switchable between microphone and line operation, allowing one compact interface to accommodate different source types. Audio is transported at 24-bit resolution with support for 44.1 kHz and 48 kHz sample rates.

Ideal Use Cases

The RU-MLB4 is suited to installed audio systems that need four channels of analog input and four channels of Dante output, together with four Dante input channels and four balanced analog outputs. Its switchable mic/line inputs make it useful when a system must accept microphones, line-level equipment, or a combination of the two. Balanced connections and detachable terminal blocks support permanent integration where secure, serviceable wiring is important.

Why Choose This Model

This model combines both directions of audio conversion in a single 5.8-inch-wide unit. Four rear-panel MIC or LINE selectors configure the analog input channels. Automatic gain provides 40 dB for condenser microphones and 60 dB for dynamic microphones, while P48 48 Vdc phantom power supports compatible condenser microphones. The phantom implementation is specified to IEC 61938:2013.

On the output side, four Dante channels are converted to balanced analog audio at a nominal +4 dBu level. Output impedance is 150 ohms balanced or 75 ohms unbalanced, and available headroom above +4 dBu is greater than 18 dB. The stated digital-to-analog operating relationship is 18 dBFS equals +4 dBu.

Installation and Integration

Network connection is provided through an RJ45 port with Link and Speed indicators. The Dante connection operates at a 100 Mbps transmission rate. Analog inputs and outputs use detachable terminal blocks, simplifying initial wiring and later equipment service. Two power connection methods are provided: a power jack and a detachable terminal block.

The RU-MLB4 requires 24 Vdc at 180 mA plus the load associated with connected phantom-powered devices. The listed recommended supplies are the PS-24AS for the USA and PS-24AX for international use. PoE Class 0 under IEEE 802.3af is listed specifically for the separate RU-MLB4P variant. The RU-MLB4 measures 5.8 inches wide, 1.7 inches high, and 5.2 inches deep. Its specified ambient operating range is 0 to 40 degrees Celsius.

Performance Highlights

The audio path covers 20 Hz to 20 kHz within plus or minus 0.5 dB. THD+N is specified below 0.1%, while noise below +4 dBu is less than -70 dB. Common-mode rejection is greater than 70 dB from 50 Hz to 120 Hz. Crosstalk is specified below 75 dB at 1 kHz from any line channel to any microphone channel and below 70 dB across 20 Hz to 20 kHz.

The inputs have an impedance greater than 1 kilohm. Four balanced outputs deliver a nominal +4 dBu signal through detachable terminal blocks. Supported digital formats are focused on professional audio transport, with 24-bit depth and selectable 44.1 kHz or 48 kHz operation; 48 kHz is the default sample rate.

What Makes It Different

The RU-MLB4 brings four configurable analog source channels and four analog destination channels onto the same Dante interface. That bidirectional arrangement reduces the need for separate input and output converters when both signal directions are required. Its combination of automatic microphone gain, switchable mic/line operation, P48 phantom power, balanced outputs, and Dante networking addresses the core conversion functions within one enclosure.

Thirteen indicators provide direct status visibility: one Power In indicator, four input signal LEDs, four output signal LEDs, two Network Sys and Sync indicators, and Ethernet Link and Speed indicators. These indicators expose power, signal, synchronization, and network status from the unit itself.

Final Assessment

The RDL RU-MLB4 is a focused choice for systems requiring four-channel analog-to-Dante and four-channel Dante-to-analog conversion. It combines configurable microphone or line inputs, professional nominal output levels, defined audio performance, detachable connections, and visible network and signal status. Its compact dimensions allow these functions to be integrated without dedicating separate devices to each conversion direction.