$100.00

Product Overview

OpenAudio L2H-1202/1204 is a dual-channel audio line matching transformer module designed to convert low-impedance (4Ω/8Ω) amplifier outputs into standard 70V/100V constant-voltage outputs, with up to 120W output capacity per channel.

The device is widely used in commercial broadcasting and background music systems, effectively solving challenges such as long-distance transmission and multiple speaker parallel connections.

This device adopts a standard 1U rack-mounted structure with an industrial-grade shielded chassis, featuring low audio loss and high operational stability. It is widely used in shopping malls, hotels, office buildings, campuses, and industrial parks for public broadcasting systems. It is a core supporting device for implementing true constant-voltage audio distribution.

Product Positioning

Product Model: OpenAudio L2H-1202/1204
Device Type: Dual-channel audio impedance/voltage matching transformer
Output Capacity: Up to 120W per channel (70V/100V constant-voltage output)
Output Mode: Selectable 70V / 100V constant voltage
Core Application: Low-impedance to constant-voltage conversion, long-distance audio transmission, distributed multi-speaker reinforcement

Key Features

Dual-channel independent operation: Each channel is fully isolated with a Max output capacity of 120W, supporting stereo or dual-zone applications without interference.
Dual voltage mode switching: Supports standard 70V and 100V constant-voltage outputs for flexible deployment based on distance and speaker configuration.
High-fidelity, low-loss design: Audio-grade transformer core with insertion loss ＜1dB and flat frequency response, ensuring accurate sound reproduction without noticeable distortion or low-frequency attenuation.
Standard rack installation: 1U rack-mount design compatible with all 19-inch racks, enabling clean installation and efficient space usage.
Industrial-grade reliability: Full metal shielding minimizes electromagnetic interference and ensures stable 24/7 operation.
Easy wiring and maintenance: Removable Phoenix connectors with clearly defined input/output sections for quick installation and servicing.

Category: Openaudio_product

Description

Description

1. Product Overview

The device is widely used in commercial broadcasting and background music systems, effectively solving challenges such as long-distance transmission and multiple speaker parallel connections.

Product Positioning

Product Model: OpenAudio L2H-1202/1204
Device Type: Dual-channel audio impedance/voltage matching transformer
Output Capacity: Up to 120W per channel (70V/100V constant-voltage output)
Output Mode: Selectable 70V / 100V constant voltage
Core Application: Low-impedance to constant-voltage conversion, long-distance audio transmission, distributed multi-speaker reinforcement

2. Key Features

- Dual-channel independent operation: Each channel is fully isolated with a Max output capacity of 120W, supporting stereo or dual-zone applications without interference.
- Dual voltage mode switching: Supports standard 70V and 100V constant-voltage outputs for flexible deployment based on distance and speaker configuration.
- High-fidelity, low-loss design: Audio-grade transformer core with insertion loss ＜1dB and flat frequency response, ensuring accurate sound reproduction without noticeable distortion or low-frequency attenuation.
- Standard rack installation: 1U rack-mount design compatible with all 19-inch racks, enabling clean installation and efficient space usage.
- Industrial-grade reliability: Full metal shielding minimizes electromagnetic interference and ensures stable 24/7 operation.
- Easy wiring and maintenance: Removable Phoenix connectors with clearly defined input/output sections for quick installation and servicing.

3. Technical Specifications

3.1 Electrical Specifications

Parameter	Specification
Number of Channels	2 / 4 channels (independent isolation)
Maximum Output Power per Channel	120W (70V / 100V line)
Maximum Input Voltage	32Vrms
Output Voltage Levels	70V / 100V (selectable)
Audio Insertion Loss	＜1dB
Frequency Response	70Hz–15kHz (±1dB, at 1W output)
Compatible Input Impedance	4Ω / 8Ω
Minimum Load Impedance (70V mode)	≥40Ω
Minimum Load Impedance (100V mode)	≥80Ω

3.2 Mechanical and Environmental Specifications

Parameter	Specification
Dimensions (W×H×D)	209mm × 44mm × 178mm 209mm × 44mm × 278mm
Net Weight	2.1kg /4.1kg
Gross Weight	2.4kg /4.4kg
Installation	19-inch rack, 1U
Chassis Material	Metal shielded enclosure
Operating Temperature	0℃–40℃
Storage Temperature	-20℃–60℃

4. Panel and Interface Description

4.1 Front Panel

4.2 Rear Panel Interfaces

All connections are located on the rear panel, divided into input, output, voltage selection, and grounding sections. Each channel is independent.

CH1 Input: Connect to amplifier CH1 low-impedance output
CH2 Input: Connect to amplifier CH2 low-impedance output
CH3Input (L2H-1204 only): Connect to amplifier CH3 low-impedance output
CH4 Input (L2H-1204 only):Connect to amplifier CH4 low-impedance output
CH1 Output: 70V/100V output to speaker line
CH2 Output: 70V/100V output to speaker line
CH3 Output (L2H-1204 only): 70V/100V output to speaker line
CH4 Output (L2H-1204 only):70V/100V output to speaker line
Voltage Selection: Independent 70V / 100V / COM terminals per channel
Ground Terminal: System grounding for noise reduction and safety
System Installation and Wiring Guidelines

5.1 System Topology

Audio Source → Power Amplifier → OpenAudio L2H-1202/1204 → Constant-voltage speaker system

5.2 Installation

Install in standard 19-inch rack
Place near amplifier to reduce cable length
Ensure proper ventilation

5.3 Wiring

Use 1.5–2.5mm² cable for amplifier input
Select voltage mode using terminal jumpers
Connect speakers in parallel
Ensure proper grounding

5.4 Load Requirements

70V mode: ≥40Ω per channel
100V mode: ≥80Ω per channel
Do not operate without load

Application Scenarios

6.1 Voltage Mode Selection

70V: short distance (<500m), dense speaker deployment
100V: long distance (500–1000m), wide-area coverage

6.2 Wiring Recommendations

Input side: shielded cable
Output side: 1.5–4mm² depending on distance

7. Maintenance and Troubleshooting

Routine Maintenance

Inspect connections regularly
Clean dust
Maintain proper environment

Common Issues

Issue	Cause	Solution
No output	Wiring or power issue	Check connections
Distortion	Overload	Reduce load
Noise	Grounding issue	Improve grounding
Overheating	Overload	Improve ventilation

Safety Instructions
- Power off before wiring
- Do not operate without load
- Avoid overload
- Do not disassemble

Standard Accessories

Main unit ×1
Rack screws ×4
Documentation

10. Engineering Notes (Critical Operation Guidelines)

The input power must not exceed the transformer’s rated power (120W per channel). For reliable long-term operation, it is recommended to operate within 70–85% of the rated capacity.

11. 70V/100V Constant Voltage: Transformer-Based vs. DSP-Limited Systems