DB-J3M

RDL DB-J3M - Mic/Line Input Panel with Transformer Isolation and Stereo-to-Mono Summing (Black Version)

The RDL DB-J3M is a complete wall-mounted audio input panel featuring a female 3-pin XLR jack and a stereo 3.5 mm mini-jack input. Designed for professional AV installations, it allows connection of both balanced microphone signals and unbalanced consumer-level line sources such as laptops, mobile devices, or media players.

The mini-jack input accepts mono or stereo signals, which are summed and converted to a balanced mono output via audio transformers that provide galvanic isolation and effective hum rejection. The line-level output is available on the rear terminal block and is intended for equipment with an input impedance of 10 kΩ or higher. The XLR input is directly wired to the rear barrier block, allowing independent use of both inputs. The black version is ideal for modern AV environments where discreet, professional appearance is essential.

Functionality

• Accepts both balanced mic and unbalanced line-level sources
• Stereo-to-mono summing and conversion to balanced output
• Transformer isolation and hum cancellation on unbalanced input
• Direct XLR-to-terminal block connection - independent from mini-jack
• Balanced line output for devices with ≥10 kΩ input impedance
• Mounts in standard wall boxes and AV cabinets

Features

• Inputs: 3-pin XLR female (gold contacts), 3.5 mm stereo mini-jack
• Output: terminal block (line: +, -, shield; mic: pin 1, 2, 3)
• Frequency response (line input): 30 Hz to 20 kHz (±1 dB)
• Power: passive (no power required)
• Dimensions: height 4.13 in, width 1.7 in, depth 2.15 in
• Mounting box required: min. width 1.80 in, depth 1.75 in
• Color: black
• Housing: metal, clearly labeled for easy installation

RDL DB-J3M combines the functionality of a professional XLR mic input with the convenience of a mini-jack line input. With transformer isolation, stereo-to-mono summing, and passive operation, it is an ideal choice for AV installations requiring reliability, compatibility, and a clean appearance - especially in the black version, suited for modern environments.