Bal. to Unbal. Audio Transformer-XLR, Phono

The RDL TX-AFC1F is a studio-quality bifilar audio transformer designed for a clearly defined interface task: converting a balanced professional audio signal on XLR to an unbalanced consumer-level signal on a phono jack. It combines balanced-to-unbalanced conversion, professional-to-consumer level conversion, and galvanic isolation in the convenient RDL TXs format. Gold contacts are provided on both the input and output connectors.

Ideal Use Cases

The TX-AFC1F is suited to connections between equipment operating at different audio levels and connector formats. Its +4 dBu balanced XLR input can interface with a professional-level source, while its -10 dBV phono output provides the corresponding consumer-level connection. This makes the model appropriate wherever balanced XLR audio must feed an unbalanced phono input without relying on connector conversion alone.

It is also applicable when galvanic isolation is required between the source and destination. The 2.5 kΩ bridging input accepts a nominal +4 dBu signal and supports a maximum input level of +22 dBu. These defined input and output characteristics make it possible to evaluate compatibility before installation.

Why Choose This Model

This model consolidates three functions into one connectorized unit: galvanic isolation, balanced-to-unbalanced conversion, and professional-to-consumer level conversion. The studio-quality bifilar transformer is the central component, while the XLR input and phono output establish a direct connection path for the specified signal formats.

Gold contacts on the input and output distinguish the connector construction, and the RDL TXs format keeps the assembly compact. The unit measures 3.17 inches wide, 1.76 inches high, and 2.06 inches deep, making its physical requirements straightforward to account for when planning an installation.

Installation and Integration

Connect the balanced source to the XLR input and route the phono-jack output to the unbalanced destination. The input is specified for +4 dBu nominal operation, with +22 dBu maximum input capability and a 2.5 kΩ bridging impedance. The output level is specified at -10 dBV. Confirm that the connected source and destination correspond to those stated levels before integration.

The TX-AFC1F is rated for an ambient operating environment of 0°C to 55°C. Its compact enclosure dimensions are 3.17 by 1.76 by 2.06 inches, equivalent to 8.05 by 4.47 by 5.23 centimeters. The listed WEEE weight is 0.56 pounds. Package dimensions are 2 by 2 by 4 inches, and the listed shipping weight is 0.62 pounds.

Performance Highlights

The specified frequency response extends from 20 Hz to 20 kHz with a tolerance of ±0.1 dB. Total harmonic distortion is stated at less than 0.06% from 50 Hz to 20 kHz with a +4 dBu input. Typical THD at 1 kHz and +4 dBu input is 0.0015%.

Common-mode rejection ratio is greater than 85 dB for the balanced input from 50 to 60 Hz. Together, these published figures describe performance across the audible frequency range while also documenting distortion and balanced-input common-mode rejection under the stated test conditions. The +22 dBu maximum input specification provides an additional concrete limit for system setup.

What Makes It Different

The TX-AFC1F does more than change connector types. It converts a balanced signal to an unbalanced signal, translates a +4 dBu professional input to a -10 dBV consumer output, and provides galvanic isolation through its bifilar audio transformer. Those functions are delivered through a connectorized XLR-to-phono configuration with gold contacts at both ends.

Its specifications are equally direct: a 20 Hz to 20 kHz response, defined THD performance, greater than 85 dB CMRR under the stated conditions, and a 2.5 kΩ bridging input. This focused design makes the model easy to assess for the exact interface it is intended to provide.

Final Assessment

The RDL TX-AFC1F is a purpose-built choice for converting a professional +4 dBu balanced XLR signal to a consumer-level -10 dBV unbalanced phono connection while maintaining galvanic isolation. Its studio-quality bifilar transformer, gold-contact connectors, compact dimensions, and documented audio specifications provide a complete set of details for selecting and integrating the unit into a compatible audio path.