Description
The HD-MA35U is a compact two-zone mixer amplifier that combines a 35 W main output and a 4 W secondary output in a single chassis. It provides mixer controls, tone shaping and a Class D amplifier topology to deliver efficient amplified audio in small- to medium-sized installations. The unit is engineered for low standby power and automatic power-up on audio detection.
The HD-MA35U features four shared inputs, two switchable mic/line inputs with phantom power and two stereo RCA inputs summed to mono. Zone 1 offers front-panel level and tone controls plus a VCA master that supports 0 to 10 Vdc or RDL remote wall controls, while Zone 2 provides rear-panel trimmers for music-on-hold or background music. A multi-band analog compressor/limiter protects the main output and increases average perceived loudness without audible distortion.
Performance specifications include low distortion and broad frequency response with THD+N under 0.5% at compressor threshold and line output distortion below 0.1%. Frequency response extends up to 25 kHz on mic to line paths and the mixers include ±10 dB treble and ±9 dB bass controls at defined frequencies. Phantom power of 24 Vdc is switchable for either microphone input and input gain trimmers allow precise preamp calibration.
Connectivity includes balanced mic/line terminal-block inputs, unbalanced RCA line inputs, dual mono RCA line outputs, a transformer-balanced 600 ohm MOH output, and detachable terminal-block speaker outputs that are switch-selectable between 4 ohm and 8 ohm. An effects send/return loop and an RJ45 VCA control port are provided, and a 24 Vdc accessory power output can feed optional RDL external modules. The unit also offers VOX or contact-closure paging priority and adjustable ducking with LED indication.
The HD-MA35U addresses common telecom and paging requirements by offering paging VOX detect, manual push-to-talk terminals, 25 dB ducking of other inputs, and a MOH output with transformer isolation and 16 dB headroom. It supports simultaneous feeding of another power amplifier via its active balanced line output, enabling cascading for larger systems. Sleep-mode timing is switch-selectable between 10 minutes and 2 hours and can be disabled for continuous operation.
Installation and operation are simplified by front-panel controls for user adjustments and rear-panel trimmers and switches for installer configuration. The included external universal power supply provides 24 Vdc and the amplifier uses soft-start switching and thermal and short-circuit protection for reliable operation. The compact chassis and low heat output from Class D stages make the HD-MA35U straightforward to mount and integrate into AV and paging systems.


