The HD-MA35A is a three input audio mixer amplifier for systems demanding a broad range of features and high energy efficiency. Two output power amplifier zones are provided, 35 W (Zone 1) and 2 W (Zone 2). The Zone 1 output is driven from a high-efficiency Class D amplifier stage. The Zone 1 amplifier output level may be VCA controlled using various optional RDL remote controls, or by industry standard 0 to 10 Vdc or 0 to 10 kOhm controls. This output provides a constant voltage (25 V, 70 V or 100 V). The Zone 2 amplifier output drives an 8 Ohm speaker and/or 600 Ohm telephone equipment. The HD-MA35A is engineered and manufactured in the U.S.A. The HD-MA35A features two mixers. The Zone 1 mixer is located on the front-panel providing user level and tone controls for the 35 W amplifier output. The tone controls adjust the equalization at the Zone 1 amplifier output. The Zone 2 mixer on the rear panel provides level trimmers normally set by the installer to provide music-on-hold and/or for background music in a small zone equipped with an 8 Ohm speaker. The Zone 2 section includes a 2 W amplifier and a 600 Ohm transformer-balanced MOH output. The HD-MA35A has three inputs that are common to both mixers. Input 1 accepts a balanced mic or line level source. Inputs 2 and 3 accept unbalanced mono or stereo line-level sources.