Headphone Amplifier Mozos HA400 — 4-channel stereo headphone amp, compact desktop unit

Mozos HA400 is a compact desktop 4-channel stereo headphone amplifier that allows a single stereo source to feed up to four independent headphone outputs. The unit is designed for straightforward distribution and level control of stereo signals without complex routing, making it suitable for monitoring, rehearsals, small project studios, classroom listening, or any setting where several listeners require the same audio feed. The physical layout and controls prioritize simple setup and reliable, low-noise operation for personal and small-group use.

Advantages

The device provides four independently adjustable stereo headphone outputs so each listener can set their preferred level while maintaining the same stereo source. Its compact desktop form factor conserves workspace and is easy to position near a mixer, audio interface, or media player. The straightforward signal path reduces the risk of latency or signal degradation, and the design focuses on dependable, low-noise amplification appropriate for passive and many active headphones. The front-panel controls and clear channel separation simplify operation for users with minimal technical experience.

Suitable for

• Home or project studios for musician monitoring
• Band rehearsals and practice sessions
• Small classroom or training environments for shared listening
• Podcast or live-stream setups where multiple hosts/guests require the same feed
• Personal listening where several headphones are needed from one source

Key specifications

• Number of headphone outputs: 4 stereo channels
• Form factor: compact desktop unit designed for proximity to source devices
• Control: independent level control for each headphone output
• Signal path: stereo input duplicated to multiple outputs with level adjustment
• Compatibility: designed to drive a range of headphones; suitable for both passive and many active models
• Typical use: monitoring, rehearsals, small-group listening and distribution of stereo audio

How to use

Connect a stereo source such as a mixer, audio interface, computer, or media player to the unit's stereo input using the appropriate cables. Plug headphones into any of the four front-panel outputs and adjust each channel's level control to achieve the desired listening volume for each person. Keep source levels at a nominal level to avoid clipping; reduce individual headphone gain if distortion or excessive loudness occurs. The unit is intended for desktop use and requires stable placement to prevent cable strain or accidental disconnection.

Usage recommendations

For consistent audio quality, use shielded cables between the source and the amplifier and set the source output to a moderate level before fine-tuning individual headphone gains. When using high-impedance headphones, increase level gradually; with very sensitive in-ear monitors or low-impedance headphones, start with low gain to avoid high volume. Maintain ventilation clearance around the unit and disconnect power before cleaning or when changing cabling in professional setups.