Description
Download Manual The HD-RA35U is a compact four-input mixer amplifier that combines paging, background music and music-on-hold capabilities in a single chassis. It provides a 35 W Class D main output and a 4 W secondary output to serve a primary zone and a small secondary zone. The unit is engineered to minimize standby power while restoring full operation automatically when audio is present – ideal for energy-conscious installations.
Key features include a front-panel paging input with VOX or push-to-talk operation, three remotely controlled VCA volume inputs for user-accessible level control, and front-panel bass and treble tone controls. The main amplifier channel uses an analog compressor/limiter that increases apparent average output without audible artifacts. The amplifier outputs are switch-selectable to drive 4 Ohm or 8 Ohm loads on the main zone and provide a transformer-balanced 600 Ohm music-on-hold output.
Performance details include Class D amplifier stages, a compressor threshold set 2 dB below rated output, low THD, and low noise figures across balanced and unbalanced inputs. Line and mic inputs accept a wide range of levels with switch-selectable phantom power on mic channels. The system meets strict energy standards and consumes less than 1 W in standby, while soft-start and internal protection prevent clicks, pops and thermal or short-circuit damage.
Connectivity covers two balanced mic/line inputs on detachable terminal blocks, two unbalanced RCA stereo inputs summed to mono, an unbalanced amp-in RCA, dual-mono line outputs on RCA, a transformer-isolated 600 Ohm MOH output, and an effects send/return loop. A RJ45 VCA control port accepts RDL wall-mounted remotes to give users local control without running audio cables. A 24 Vdc accessory output is provided to power optional external modules.
The HD-RA35U suits paging systems, small-background-music applications, and music-on-hold integration in telephony systems. Use it in reception areas, retail spaces, small meeting rooms, or as a dedicated paging amplifier in distributed audio systems. Its VOX or contact-closure ducking ensures priority paging that reliably attenuates background sources during announcements.
Installation is installer-friendly with rear-panel gain trimmers, mic/line switching, sleep-mode delay DIP switches, and detachable speaker terminals. The included external 24 Vdc power supply simplifies mounting and service access. Robust front-panel and rear-panel indicators, remote control compatibility, and a metal chassis provide dependable operation and long-term reliability.