Rapco Horizon ISO BLOX In-Line Mic-Level Isolation Transformer

The Rapco Horizon ISO BLOX is an in-line isolation transformer designed for microphone signal paths in live sound, studio, and broadcast environments. It enables ground-loop isolation for audio engineers and technicians, supporting clean signal transfer between microphones and mixing consoles. This makes it ideal for professional audio systems where hum and noise elimination is critical.

This unit installs directly into a microphone line using XLR connections on both ends. It provides isolation while maintaining a consistent mic-level signal path and impedance relationship. The design allows the transformer to operate transparently without altering signal level.

In real-world use, the ISO BLOX supports reliable noise reduction across portable, installed, and broadcast audio systems. It is suited for applications where electrical grounding conditions vary and clean microphone signals must be preserved. The compact enclosure allows unobtrusive integration into complex signal chains.

Key Features

• In-Line Isolation Transformer: Designed for microphone-level signal paths
• Ground Loop Hum Reduction: Helps eliminate unwanted noise caused by grounding issues
• XLR Female to XLR Male: Integrates directly into standard microphone cabling
• 1-to-1 Level Matching: Maintains signal level without attenuation or gain
• Compact Rugged Housing: Suitable for stage, studio, and broadcast applications

Technical Specifications

Product Type
In-Line Mic-Level Isolation Transformer

Signal Application
Microphone Lines

Input Connector
XLR Female

Output Connector
XLR Male

Impedance
600 ohms

Level Matching
1-to-1

Construction
Compact metal enclosure