Description
Download Manual The HD-RA35UA is a compact mixer amplifier that combines a four-input mixer with two Class D amplifier zones for background music and paging applications. Zone 1 delivers 35 W RMS as a constant-voltage output selectable for 25 V / 70 V / 100 V. Zone 2 provides a 4 W RMS low-impedance output and a transformer-balanced 600 ohm MOH output.
Key features include front-panel paging control, three remote-controllable VCA inputs for user volume adjustment, and a front-panel VOX/push-to-talk paging input. The unit employs analog-filtered Class D amplifier stages and an analog compressor/limiter on the Zone 1 output to preserve audio dynamics while preventing clipping. Tone controls for bass and treble are provided and can be switched to affect the line output.
The HD-RA35UA is engineered for energy efficiency and automatic standby operation when audio is absent, consuming less than 1 W in sleep mode. The Zone 1 compressor increases average perceived output for transient-heavy program material without audible pumping, and a front-panel LED indicates compressor activity. Inputs 1 and 2 accept mic or line level with switchable 24 V phantom power and rear-panel gain trimmers for precise gain staging.
Connectivity covers balanced terminal-block mic/line inputs, unbalanced RCA line inputs, a send/return effects loop, dual-mono RCA line outputs, and an RJ45 remote control jack for RDL VCA wall controllers. A 24 Vdc ground-referenced output is provided to power optional external RDL modules. The unit ships with an external 24 Vdc power supply and includes detachable terminal blocks for amplified outputs.
Typical installations include small retail stores, houses of worship, offices requiring paging and background music, and systems needing music-on-hold for telephone equipment. The VOX or push-to-talk paging options allow automatic ducking of background sources by 25 dB and a rear-panel trimmer sets the fade-up delay. The Zone 2 mixer and MOH outputs support small-zone speakers and telephone hold interfaces.
Installation and operation are straightforward for installers and end users. Rear-panel DIP switches select sleep delay from 10 minutes to 2 hours or disable sleep entirely for continuous operation. Thermal and short-circuit protections are integrated and the Class D topology minimizes heat generation for reliable long-term use.