Stereo Audio/Composite Video "HUM KILLER"

The RDL EZ-HK3 Stereo Audio/Composite Video HUM KILLER is designed for audio and video ground-loop hum elimination in systems using unbalanced stereo audio and composite video. It combines stereo galvanic isolation with 75-ohm composite video galvanic isolation in a compact case. Input and output connections use RCA phono jacks, while a ground-lift switch controls the output-ground relationship for both signal types. Audio and video gain is unity nominal through a passive circuit.

Ideal Use Cases

The EZ-HK3 fits systems where a ground loop affects both the stereo audio path and the composite video path. Its interfaces are specified for -10 dBV nominal stereo audio and 1 V p-p nominal composite video output. It can be used as a portable device or incorporated into a permanent installation. The 1/6-rack-width mounting size and 2.9-inch by 3-inch case footprint accommodate compact equipment layouts while retaining RCA connectivity for both signal paths.

Why Choose This Model

Choose this model when an installation calls for stereo audio and composite video isolation in the same unit. The EZ-HK3 carries both paths through RCA input and output connections and provides a shared, switch-selectable output ground lift. The audio input is ground-isolated, and the selectable lift affects the audio and video output grounds. This combination directly supports its purpose of eliminating ground-loop hum while maintaining nominal signal gain.

Installation and Integration

Connect the stereo audio path to the RCA phono input and output jacks at a nominal level of -10 dBV. Connect the composite video path through its RCA connections; the video output is specified as 1 V p-p nominal with a 75-ohm output impedance. Set the ground-lift switch according to the required output-grounding arrangement. The switch lifts the audio and video grounds together. For fixed placement, allow for a case measuring 2.9 inches (7.4 cm) wide by 3 inches (7.6 cm) deep. The mounting size is 1/6 rack width, and the unit is specified for either portable use or permanent installation.

Performance Highlights

The audio path has a frequency response of 20 Hz to 20 kHz within ±1 dB. Stereo audio input is provided on RCA phono jacks at -10 dBV nominal and is ground-isolated. Stereo audio output is also provided on RCA phono jacks at -10 dBV nominal. Audio input and output impedances are both specified at 10 kΩ. For composite video, the nominal output is 1 V p-p with a 75 Ω output impedance. Video bandwidth extends from 40 Hz to greater than 5 MHz, providing the stated excellent response at both low and high video frequencies. Audio and video gain remains at unity nominal through the passive circuit.

What Makes It Different

The defining feature of the EZ-HK3 is its combined handling of an unbalanced stereo audio path and a 75-ohm composite video path. Both receive galvanic isolation within one compact unit, and both output grounds are controlled by the same selectable ground-lift function. The combination of RCA connectivity, passive unity-gain operation, portable or permanent deployment, and a 1/6-rack-width mounting format gives the model a clearly defined role in analog audio and composite video systems.

Final Assessment

The RDL EZ-HK3 is a focused ground-loop hum eliminator for systems using -10 dBV stereo RCA audio and 1 V p-p composite video. Its ground-isolated audio input, composite video galvanic isolation, switch-selectable output ground lift, broad stated video bandwidth, full-range audio response, and nominal unity gain provide a complete set of documented features for isolating both signal paths in portable or permanently installed applications.