Unbalanced Input Transformer

Ideal Use Cases

The RDL TX-J3 is designed for applications that need to convert an unbalanced stereo source into a summed balanced mono output. It is suited to signal paths in which the source provides stereo audio through a mini-jack or a pair of RCA phono jacks, while the receiving connection requires balanced mono wiring. This makes the TX-J3 a focused interface for combining left and right input channels into one mono output without requiring an external power supply.

Its compact format also supports integration where available equipment space is limited. The case measures 3.0 inches high, 1.2 inches wide, and 1.5 inches deep, increasing to 1.8 inches deep with the connectors included.

Why Choose This Model

The TX-J3 combines three useful functions in one passive module: accepting an unbalanced stereo input, summing that input to mono, and presenting the result as a balanced output. Input connection flexibility is provided by a mini-jack and dual RCA phono jacks. On the output side, a detachable terminal block provides plus, minus, and ground connections.

Because the module is passive, it does not require a power supply. This keeps the signal conversion independent of an additional powered component and eliminates the need to provide a separate power connection for the transformer. The clearly defined input and output formats also make the unit straightforward to match with compatible source and destination equipment.

Installation and Integration

Connect the unbalanced stereo source through the available mini-jack or dual RCA phono input connection. The transformer then converts and sums the stereo input into a balanced mono output. The detachable terminal block provides separate plus, minus, and ground output connections for integration with balanced wiring.

The TX-J3 has a case depth of 1.5 inches and an overall depth of 1.8 inches when the connectors are included. Its height is 3.0 inches, and its width is 1.2 inches. These measurements are also specified as 7.6 cm high, 3.0 cm wide, 3.8 cm deep at the case, and 4.6 cm deep with connectors. No power-supply placement or power wiring is needed because the module operates passively.

Performance Highlights

At line level, the TX-J3 provides a specified frequency response of 30 Hz to 20 kHz within ±1 dB. This published range defines the module’s response across the stated audio bandwidth while it performs stereo summing and unbalanced-to-balanced conversion.

The balanced mono output is carried through the detachable terminal block, while the input side supports two common unbalanced connector formats. The design therefore brings the required connector transition and signal-format conversion together in a single unit.

What Makes It Different

The defining feature of the TX-J3 is its specific combination of stereo summing and output balancing. It is not limited to changing connector types: it accepts an unbalanced stereo signal and produces one summed balanced mono output. The choice of mini-jack or dual RCA phono input connections accommodates either of the listed source interfaces without changing the output wiring format.

Passive operation is another distinguishing characteristic. The conversion does not depend on a separate power supply, yet the module retains a stated line-level frequency response of 30 Hz to 20 kHz within ±1 dB. Its detachable output terminal block also allows the plus, minus, and ground wiring to be handled as a removable connection.

Final Assessment

The RDL TX-J3 is a purpose-built option for converting unbalanced stereo audio into a summed balanced mono signal. Its mini-jack and dual RCA phono input choices, detachable plus-minus-ground output terminal block, passive operation, compact dimensions, and published line-level response provide the essential details needed to evaluate it for a compatible audio path. For installations centered on this exact conversion, the TX-J3 offers the required signal handling in one compact module without a power-supply requirement.