MACKIE HM-4 - Ultra-compact 4-way headphone amplifier

MACKIE HM-4 – Ultra-compact 4-way headphone amplifier

The Mackie HM-4 is a desktop headphone amplifier that lets you share a single stereo source with up to four independent pairs of headphones. Each output features individual level controls, delivering customized mixes without interference. Built with “Built-Like-A-Tank™” ruggedness, it is powered by the included 12V DC adapter and features an LED power indicator. Its ultra-compact design fits on any desktop or rack and is perfect for studios, home environments, rehearsal rooms, or recording stations where multiple users need to listen to the same signal with independent settings.

Main features

• Input: 1 × 1/4″ TRS jack (balanced/unbalanced), maximum level +22 dB.
• Input impedance: 10 kΩ.
• Outputs: 4 × 1/4″ TRS unbalanced jack (stereo), impedance 47 Ω each channel.
• Controls: 4 independent volume potentiometers, LED power indicator.
• Frequency response: 20 Hz – 20 kHz ±1 dB.
• Power supply: 12 V DC adapter (included), consumption < 220 mA.
• Construction: Ultra-compact “Built-Like-A-Tank™” metal housing.
• Dimensions: 10.9 × 5.4 × 10.2 cm (W × H × D).
• Weight: 0.2 kg.

User benefits

• Custom Mixes: Each listener adjusts their own level without affecting the rest.
• Easy installation: Direct connection of any stereo source via TRS jack.
• Portability: Compact and lightweight design for studio, home or rehearsal use.
• Robustness: Heavy-duty metal construction for intensive daily use.
• Full compatibility: Works with any device that offers a headphone or line output.

Use cases

• Multi-track recording studios for distributing headphones to musicians.
• Domestic spaces where several users want to listen to music together.
• Rehearsal rooms for monitoring guide tracks with several members.
• Dubbing or editing booths where the director and editor need separate audio.

Frequently Asked Questions

• How many headphones can I connect? Up to four pairs, each with its own volume control.
• What type of signal does the input support? Connect to headphone or line outputs via balanced or unbalanced TRS jacks.
• Do you need an external power supply? 12 V DC adapter included; just plug into the mains.
• Is it suitable for high impedance? Yes; the 47 Ω output efficiently handles headphones of common impedances.

Description for projects

Mackie HM-4 amplifier with 1 TRS stereo input, 4 TRS outputs with independent volume, 20 Hz–20 kHz response, 12 V DC adapter, ultra-compact metal housing measuring 10.9 x 5.4 x 10.2 cm and weighing 0.2 kg.