Unbalanced to Balanced Converter-6 Channel

The RDL FP-UBC6 is a connectorized FLAT-PAK audio converter that provides six identical circuits for unbalanced-to-balanced audio conversion. Each channel includes a separate gain control, allowing six signals to be adjusted independently while producing a rated +4 dBu output. Its compact enclosure supports cabinet, shelf, or rack mounting and combines flexible integration with low-noise, low-distortion performance.

Ideal Use Cases

The FP-UBC6 is suited to audio systems that need to connect as many as six unbalanced sources to balanced audio lines. Its independent channels make it useful when several signals require conversion and individual level adjustment within the same installation. The balanced outputs have a 150 Ω impedance and can drive 600 Ω or 10 kΩ lines. Because the output configuration may also be used unbalanced, the converter can accommodate systems containing a mixture of balanced and unbalanced destinations.

Why Choose This Model

Six conversion circuits in one enclosure reduce the need for multiple individual converters. Each channel has its own adjustable gain control, with a specified range of 5 dB to +10 dB relative to a +4 dBu output for a −10 dBV input. This channel-by-channel adjustment is valuable when source levels differ or when the output of each circuit must be set independently. The 10 kΩ unbalanced input impedance and +4 dBu rated output provide clearly defined operating points for system planning.

The FP-UBC6 also delivers the mounting convenience associated with the RDL FLAT-PAK format. Its enclosure measures 1.29 inches high, 3.25 inches wide, and 8.55 inches long, providing six channels in a space-conscious form that can be installed in a cabinet, placed on a shelf, or incorporated into a rack-mounted system.

Installation and Integration

The converter requires a ground-referenced 24 Vdc supply at 75 mA. The recommended power supplies are the PS-24AS for the USA and the PS-24AX for international use; the power supply is not included. The specified ambient operating range is 0° C to 55° C.

For output integration, each channel presents a 150 Ω balanced output and is specified to drive either 600 Ω or 10 kΩ lines. Balanced or unbalanced output configurations are supported. Separate gain controls permit adjustment after the converter has been connected, while the connectorized design keeps all six conversion circuits together in one unit. Installation documentation is available through the FP-UBC6 specification sheet, and American DXF resources are identified for the engineering functional block and front panel diagram.

Performance Highlights

The FP-UBC6 covers a frequency range of 20 Hz to 40 kHz within ±0.25 dB. Total harmonic distortion is specified below 0.05%, with a typical value of 0.01% at 1 kHz, while intermodulation distortion is below 0.02%. These figures support the model’s stated low-noise and low-distortion conversion capability.

Noise is specified below −90 dB when referred to +4 dBu across 20 Hz to 20 kHz. Crosstalk is better than 80 dB over the same frequency range, helping maintain separation among the six circuits. At the rated +4 dBu output level, available headroom exceeds 18 dB. Together, the wide frequency response, controlled distortion, low noise, channel separation, and headroom define the converter’s audio performance.

What Makes It Different

The distinguishing feature of the FP-UBC6 is its combination of six identical conversion channels, individual gain trim, and flexible mounting. Rather than providing only a fixed conversion stage, it allows each channel to be adjusted separately. It also combines unbalanced inputs with outputs that support balanced or unbalanced configurations, making the unit adaptable to different signal paths without changing models.

Its FLAT-PAK enclosure concentrates these capabilities into a chassis measuring less than 1.3 inches high. The connectorized format, multiple mounting options, and single 24 Vdc power requirement simplify the physical organization of a six-channel conversion system.

Final Assessment

The RDL FP-UBC6 is a focused solution for converting up to six unbalanced audio signals while retaining individual control over channel gain. Its +4 dBu output, 20 Hz to 40 kHz response, low distortion, better-than-80 dB crosstalk, and greater-than-18 dB headroom provide a detailed performance foundation. Cabinet, shelf, or rack mounting further supports integration wherever six-channel conversion is required.