Zoom ZHA-4 4-Channel Portable Headphone Amplifier

The Zoom ZHA-4 is a compact stereo headphone amplifier that distributes one audio source to up to four listeners. It is designed for situations where a recorder, mixer, computer interface, or other device has only one headphone or line output. Each listener receives a dedicated 3.5 mm headphone connection with individual level control.

This amplifier is well suited to podcast sessions, band rehearsals, location recording, video production, and small collaborative monitoring setups. Individual volume knobs let each user set a comfortable listening level without changing the other outputs. Separate mute buttons also allow one listener's feed to be silenced independently when needed.

The ZHA-4 is built for stereo monitoring, taking a stereo line or headphone signal through its 3.5 mm input and routing it to four powered headphone outputs. Its 24 dB gain, 10 Hz–50 kHz frequency response, and dynamic range of at least 100 dB support clear monitoring across a wide audible range. A +18 dBu clipping level provides useful headroom for compatible source equipment.

Portable power options make the ZHA-4 practical for fixed and mobile work. It can run from two AA batteries or from a USB-C 5 V, 1 A external power source such as a USB AC adapter or portable battery. A front power indicator shows normal power in green and warns of low battery power in red.

The ZHA-4 fits easily between a source device and multiple wired headphones, making it a straightforward expansion tool rather than a replacement for a mixer or audio interface. Use the included stereo mini cable to connect a compatible source, then attach up to four pairs of headphones. It is especially useful when several people need to monitor the same stereo program while retaining personal volume and mute control.

Key Features

• Four Headphone Outputs: Connect up to four sets of 3.5 mm headphones to one stereo source.
• Individual Volume Controls: Set each listener's headphone level independently.
• Channel Mute Buttons: Mute any individual output without changing the remaining channels.
• Stereo Mini Input: Accepts a stereo line or headphone output from compatible audio equipment.
• Dual Power Options: Operates from two AA batteries or USB-C external power.
• Portable Monitoring Design: Adds shared headphone monitoring to compact recording and production systems.

Design & Installation

The ZHA-4 uses a compact enclosure with four panel-mounted 3.5 mm headphone jacks, individual rotary volume controls, dedicated mute buttons, a power switch, and a status indicator. Zoom specifies the unit at 130 × 70 × 52 mm and 180 g, keeping it easy to place beside a recorder, mixer, or workstation. The manufacturer does not specify the enclosure material.

Connect the stereo mini input to the line or headphone output of a compatible source using the included stereo mini cable or another suitable 3.5 mm stereo cable. Connect up to four 3.5 mm headphones, set each channel's volume as needed, and select AA or USB-C power with the power switch. For longer sessions, use a USB-C power source rated for 5 V DC and 1 A; for portable use, install two compatible AA batteries.