35 Watt Remote Mixer Amplifier -USA Power Supply

Ideal Use Cases

The RDL HD-MA35UA is designed for systems that combine background music, paging, and music-on-hold. Its Zone 1 mixer provides individual front-panel level controls for four inputs, while Zone 2 delivers a separate 4 W RMS output into 8 ohms with rear-panel mixing controls. This combination supports installations that need a 35 W RMS main amplifier, a lower-power secondary zone, and straightforward access to daily volume and tone adjustments.

Why Choose This Model

Two balanced inputs can be switched between microphone and line operation, while two stereo RCA inputs are summed for unbalanced sources. Each microphone input offers switch-selectable 24 Vdc phantom voltage. Front-panel bass and treble controls provide tonal adjustment with center detents, and four signal-present indicators show activity for the main mixer inputs. The HD-MA35UA also includes automatic Input 1 VOX priority sensing or manual priority activation through contact closure to ground. Inputs 2, 3, and 4 can be individually selected for nominal 25 dB ducking.

Installation and Integration

Balanced inputs and amplified outputs use detachable terminal blocks, while unbalanced connections are provided on RCA jacks. Zone 1 supplies 35 W RMS at 25, 70, or 100 V. Zone 2 supplies 4 W at 8 ohms through a detachable terminal block. The unit also provides dual-mono RCA outputs from the main mixer, with rear-panel selection for flat or equalized output, plus a balanced Zone 2 mixer output.

An RCA effects loop exposes the main mixer preamplifier output and power-amplifier input, with a rear-panel bypass switch. The transformer-isolated music-on-hold output operates at 0 dBu nominal into 600 ohms with 16 dB of headroom. A 24 Vdc, 100 mA output is available for powering an external RDL module. Remote control is supported through an RJ45 VCA connection accepting 0 to 10 Vdc and compatible with RDL VCA wall controls. Input 1 can be included in or excluded from master VCA adjustment for paging applications.

The included power supply accepts 100 to 240 Vac at 50-60 Hz and provides 24 Vdc to the amplifier chassis. The amplifier measures 3.5 inches high, 8.5 inches wide, and 10 inches deep, with a weight of 7.3 pounds.

Performance Highlights

The main amplifier reaches 35 W RMS, while an integrated compressor has a threshold 2 dB below rated output and automatically adjusts its attack and release times. Main-amplifier THD+N is less than 0.5% at 1 kHz at the compressor threshold, while the main line output is rated below 0.1% THD+N. Constant-voltage amplifier response is within 3 dB from 50 Hz to 18 kHz, and 4/8-ohm response is within 1 dB from 50 Hz to 20 kHz.

Mixer response varies by input type: microphone-to-line response is within 1.5 dB from 40 Hz to 25 kHz, balanced line-to-line response is within 1 dB from 20 Hz to 20 kHz, and unbalanced line-to-line response is within 0.5 dB from 20 Hz to 20 kHz. Front-panel tone controls provide 10 dB of adjustment at 10 kHz and 9 dB at 100 Hz.

What Makes It Different

The HD-MA35UA combines two amplifier zones, paging priority, music-on-hold connectivity, remote master-level control, and an effects loop in one unit. Its automatic sleep mode consumes less than 1 W for the amplifier and included power supply. The sleep delay is switch-selectable from 10 minutes to two hours in 10-minute increments and can also be disabled. After input audio is detected, the nominal active-mode delay is two seconds.

Nine indicators provide operating feedback, including four front-panel signal indicators, compressor activity, power and standby status, rear-panel VU indication for Inputs 1 and 2, and a ducking threshold indicator. Rear-panel controls provide access to input gain, microphone or line selection, phantom voltage, ducking targets, VOX sensitivity, sleep timing, effects-loop bypass, output EQ routing, VCA paging bypass, and Zone 2 mixing levels.

Final Assessment

The RDL HD-MA35UA brings together a 35 W constant-voltage main zone, a 4 W secondary zone, flexible microphone and line inputs, priority ducking, remote VCA control, and automatic energy-saving operation. It is specifically equipped for integrated background-music, paging, and music-on-hold systems and includes the power supply for the USA configuration.