HUM KILLER Audio Isolation Module

The RDL AV-HK1X HUM KILLER is a balanced mono audio isolation module designed for line-level ground-loop elimination. It provides galvanic isolation in a rugged field case and can be used as either a portable solution or part of a permanent installation. With +4 dBu nominal input and output levels, the module is intended for professional audio sources and grounded downstream equipment.

Ideal Use Cases

The AV-HK1X is suited to balanced mono audio paths affected by a ground loop. A mixer, preamplifier, or other professional audio product can feed the module, with its output connected to the input of a grounded amplifier or mixer. This focused signal arrangement makes the module appropriate for field systems that need portable isolation as well as installed systems requiring a permanent ground-isolation point. Its specified +4 dBu nominal operating level aligns with the professional audio equipment identified for use with the module.

Why Choose This Model

The defining capability of the AV-HK1X is balanced mono galvanic isolation for a line-level signal. Both its input and output are rated at +4 dBu nominal, while its frequency response extends from 20 Hz to 50 kHz within ±0.1 dB. The combination of a dedicated ground-loop elimination function, a rugged enclosure, and clearly defined signal connections makes it a practical choice when the requirement is isolation rather than broader audio processing. Its portable-or-permanent design also allows one model to serve different installation formats.

Installation and Integration

The source device connects to the AV-HK1X input. Supported source examples identified for the module include a mixer, preamplifier, or another professional audio product. The module output then connects to the input of the grounded amplifier or mixer in the system. At audio frequencies, the input jack is electrically isolated from both the case and the output ground at pin 1. The output jack is connected to the case shield. Following this input-to-output orientation places the specified isolation between the user audio source and the grounded downstream component. The module is intended for operation in ambient temperatures from 0° C to 55° C.

Performance Highlights

The AV-HK1X specifies a frequency response of 20 Hz to 50 kHz with a tolerance of ±0.1 dB. Its THD+N specification is less than 0.15% from 20 Hz to 20 kHz when measured with a 150 Ω source and 10 kΩ load. At 1 kHz, the listed THD+N figure is 0.002%. Nominal input and output levels are both +4 dBu. These published values provide concrete criteria for evaluating the module within a balanced professional line-level signal path, including its operating level, response range, and stated distortion performance under the supplied measurement conditions.

What Makes It Different

This model combines line-level ground-loop elimination and balanced mono galvanic isolation in a rugged field case. It is explicitly designed for portable or permanent use, allowing the same isolation function to be placed in temporary field arrangements or fixed systems. The enclosure uses the RDL Dark ULTRASTYLE™ finish, described as dark gray with beige lettering. Its height is 1.75 inches unmounted and 1.95 inches mounted, while its width is 2.90 inches. The specified operating range of 0° C to 55° C further defines the environments in which the unit is intended to operate.

Final Assessment

The RDL AV-HK1X is best matched to a balanced mono, +4 dBu audio path that requires galvanic ground isolation between a professional source and a grounded amplifier or mixer. Its dedicated connection arrangement, 20 Hz to 50 kHz frequency response, published THD+N figures, and rugged portable-or-permanent enclosure provide a well-defined solution for line-level ground-loop elimination. For systems that fit this signal format and grounding arrangement, the AV-HK1X offers a specific isolation function with measurable performance parameters.