TX-J3

RDL TX-J3 - Passive Audio Input Transformer, Unbalanced Stereo to Balanced Mono

The RDL TX-J3 is a passive audio input module designed for professional AV installations requiring the conversion of two unbalanced line-level stereo signals into a single balanced mono output. It performs the conversion without gain, while effectively cancelling hum and interference typical of unbalanced connections.

The front panel features two gold-plated RCA jacks and a Mini-jack input for mono or stereo consumer-level sources. When a Mini-jack is connected, the RCA inputs are automatically disabled. Inputs L and R are summed and balanced via audio transformers configured to reject induced hum. The line-level output is available on a detachable terminal block, ready for connection to equipment with 10kΩ or higher input impedance.

Note: The TX-J3 does not provide gain. The balanced output level is not a standard +4dBu. For installations requiring +4dBu or when input levels are low, RDL’s TX-LC2 is recommended.

Functionality

• Inputs: 2 x RCA or Mini-jack (auto-switching)
• Stereo to mono summing with balanced output
• Unbalanced → balanced conversion without gain
• Hum cancellation on unbalanced inputs
• Frequency response: 30Hz-20kHz (±1dB)
• Passive design - no power required

Features

• Compact audio input module
• Gold-plated RCA jacks - high signal integrity
• Mini-jack disables RCA inputs automatically
• Output via terminal block - easy AV system integration
• Ideal for education, conferencing, AV installations
• Compatible with other RDL modules

RDL TX-J3 is the ideal solution for AV installations requiring passive stereo-to-mono summing and unbalanced-to-balanced conversion without gain. Use it standalone or as part of a complete AV system.