Discover reliable audio distribution with this used Mackie HM400 Headphone Amplifier, in great condition and fully tested for optimal performance. Ideal for studios, podcasting, or live sound setups, the HM400 delivers clear, powerful headphone amplification across four independent channels. Each channel features its own volume and EQ controls, plus dual headphone outputs for flexible monitoring. With a total of 12 headphone outputs and stereo main inputs, this rack-mountable unit supports both balanced and unbalanced connections. Whether you're tracking multiple musicians or managing complex mixing sessions, the HM400 ensures accurate headphone monitoring with minimal noise and maximum clarity.