Multi-Person Monitoring, All-in-One Solution

Whether in the recording studio, rehearsal room, or live streaming venue, multi-person monitoring of the same audio source has always been an "invisible pain point"—insufficient ports, inconsistent volume levels, degraded sound quality, and cumbersome operations. To address this, we present the HA408 Multi-channel Stereo Headphone Amplifier. Debuting in a fresh Prussian Blue finish, it offers a concise and efficient solution for collaborative team monitoring.

Prussian Blue: Sophisticated and Stylish

The HA408 features a classic Prussian Blue metal casing. It is low-key yet elegant, combining a professional aesthetic with high recognizability. It blends seamlessly into various environments—be it a recording studio, stage, or live streaming room—offering a sophisticated presence without being overly conspicuous.

Four-Channel Output, Supporting Up to 8 Headphones

The HA408 is equipped with four independent output channels. Each channel provides both 6.35mm and 3.5mm headphone jacks, allowing the four channels to connect up to 8 pairs of headphones simultaneously. Whether for band rehearsals, classroom monitoring, or recording team collaboration, it ensures every member hears the audio content synchronously and stably.

Each output channel features an independent volume knob (LEVEL 1–4), allowing members to adjust their monitoring volume according to personal preference without interference. There is no need to "compromise" on a unified volume; everyone listens at their own level, making overall coordination much smoother.

Three Inputs: Mix or Single-Source, Your Choice

On the input side, the HA408 integrates RCA, 3.5mm, and 6.35mm interfaces, capable of connecting to various audio sources such as phones, mixing consoles, computers, and DVD players simultaneously. The three signals are automatically mixed for output, enabling parallel monitoring of vocals, backing tracks, and effects without the need for an extra mixing console.

If only a single audio source is needed, any interface can be used independently, offering flexibility for different scenarios.

Essential Features, Fully Equipped

One-Touch Mute: Each input is equipped with an independent mute switch. Press to mute, release to restore, facilitating rehearsal communication or the quick removal of a specific signal.

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Mono/Stereo Switch: Press the switch to enter Mono mode, release to restore Stereo. This is convenient for phase troubleshooting, mix checking, or single-ear monitoring.

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Metal Anti-Interference Body: The steel casing effectively shields against external electromagnetic interference. It also dissipates heat quickly and is durable, making it suitable for prolonged use in professional environments.

Core Audio Quality, Noise-Free Monitoring

The core is powered by the original JRC NJM4580 professional audio amplifier chip, featuring low input noise and low distortion. It reduces signal interference and distortion from the source, ensuring high-fidelity audio amplification. Sound details are clearly presented, effectively eliminating background noise and static.

With a gain of 25dB per channel, the output power is ample, supporting headphones with impedance ranging from 16Ω to 250Ω, easily meeting daily professional monitoring needs.

Core Specifications

Input Interfaces: 3.5mm / 6.35mm / RCA

Output Interfaces: 6.35mm + 3.5mm per channel

Input Impedance: 20kΩ

Gain: 25dB

Signal-to-Noise Ratio: 76dB @ 1V

Distortion: 0.004% @ 1V

Output Power (32Ω): 125mW

Power Supply: DC5V 2A (Type-C / USB)

Dimensions: 140 × 98 × 31 mm

Net Weight: 408g

Stable, Flexible, and Plug-and-Play

The HA408 utilizes universal DC5V USB power, making it plug-and-play with no complex setup required. Compact and space-saving, it delivers robust driving power.

From the rehearsal room to the recording studio, from the classroom to the live streaming backstage—HA408 ensures multi-person monitoring is no longer a compromise.