The Sanctuary Perspective

The Radial Highline Stereo is a high-performance, 2-channel passive line isolator built to solve complex ground loop hum, buzz, and impedance matching issues between line-level audio equipment. Engineered specifically for demanding wet/dry/wet guitar rigs, multi-amp setups, pedalboard interfaces, and professional studio racks, the Highline provides complete galvanic isolation without altering your natural tone. Driven by two custom-wound Radial Eclipse transformers, it transparently handles massive signal levels from line-level preamp outputs, modeling processors, and audio interfaces with ruler-flat frequency response.

Product Intelligence & Signal Integrity Profile

• Best For: Complex Guitar Rig Interfaces (Wet/Dry/Wet), Pedalboard-to-FOH Routing, Stereo Modeler Outputs, Synthesizers, and Studio Line-Level Isolation.
• Sound Character: Completely transparent and uncolored with 10Hz to 40kHz linear bandwidth, zero active noise floor, and pristine phase response.
• Compared To: Offers higher signal handling headroom and wider frequency bandwidth than standard budget line isolators, utilizing high-grade Eclipse nickel-core transformers designed specifically for high-level line signals.
• Sanctuary Expert Note: "If you are running complex multi-amp setups, digital modelers, or stereo pedalboards into different power amps or FOH channels and hearing a high-pitched digital whine or 60-cycle ground hum, the Highline Stereo is the ultimate dead-silent fix."

Key Features & Engineering Highlights

• Dual Radial Eclipse Transformers: Custom-wound nickel-core transformers isolate audio channels to eliminate ground loops while delivering ruler-flat signal transfer from 10Hz to 40kHz.
• High Signal Handling & Low Distortion: Engineered to accept up to +22dBu input levels without saturation or phase distortion, making it ideal for hot line-level rig feeds.
• Independent Channel Ground Lifts: Dedicated ground lift switches for left and right channels immediately disconnect signal grounds to kill 60-cycle hum and buzz.
• Flexible I/O Connectivity: Features balanced ¼" TRS inputs and outputs alongside 3.5mm mini-stereo pass-through routing for seamless integration into pedalboards, rack drawers, or desktop setups.
• 14-Gauge Tour-Grade Construction: Built inside Radial's legendary "book-end" heavy-duty steel chassis with an I-beam internal structure that completely protects internal components from stage mechanical stress.

Technical Specifications

• Audio Circuit Type: Passive, Transformer-Coupled Line Isolator
• Number of Channels: 2 (Stereo or Dual Mono)
• Transformers: Dual Custom Radial Eclipse Nickel-Core
• Frequency Response: 10Hz – 40kHz (± 0.5dB)
• Dynamic Range: > 135dB
• Maximum Input Level: +22dBu @ 1kHz
• Total Harmonic Distortion (THD): 0.002% @ 1kHz (+4dBu)
• Input Impedance: 10kΩ Balanced / Unbalanced
• Output Impedance: 10kΩ Balanced / Unbalanced
• Inputs: 2 x 1/4" TRS, 1 x 3.5mm Stereo TRS
• Outputs: 2 x 1/4" TRS, 1 x 3.5mm Stereo TRS
• Switches: Ground Lift (CH 1 & CH 2)
• Power Requirement: None (100% Passive Operation)
• Chassis: 14-Gauge Steel Shell with Powder Coat Finish

Audio circuit type: Passive, transformer based
Transformer: JT-11-YMPC
Number of channels: Two channels (dual mono)
Frequency response: 20Hz ~ 20KHz (± 0.05dB)
Total harmonic distortion: <0.05% from 20Hz ~ 20kHz / -10dB, 0.0008 @1kHz / -10dB
Phase Deviation: ±0.3° from 20Hz ~ 20kHz / -10dB
Signal to Noise: 112dB

Features

Ground lift
Input Connectors: XLR Sum, Thru Sum

General

Construction: 14-gauge steel outer shell & 16-gauge chassis
Finish: Durable powder coat
Size (L x W x D): 5" x 3.3" x 1.8" (127mm x 84.1mm x 45.5mm)
Shipping size (L x W x D): 6.5" x 4" x 3" (165mm x 102mm x 76mm)
Power: Passive, no power required
Conditions: For use in dry locations only between 5°C and 40°C
Warranty: Radial 3-year, transferable