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.
Three inputs with individual front-panel volume controls
Bass and Treble tone controls
Designed for background music with paging and music-on-hold
Master volume VCA controlled with remote adjustment capability
Manual or automatic (VOX) priority ducking
Balanced inputs and amplified outputs on detachable terminal blocks
Unbalanced inputs and outputs on RCA jacks
Includes power supply
High-efficiency Class D operation
Amplifier Signal Type - Audio
Amplifier Type - Power Amplifier
Spec Sheet available - Yes
Amplifier Zones (2)::
Zone 1 (Main): 35 W RMS, front-panel mixer (user controls); Zone 2: 2 W RMS (8 Ohms), rear-panel mixer (trimmers)
Audio Inputs (3)::
Balanced, mic or line switch selectable on terminal block; 2, unbalanced stereo summing inputs on RCA jacks
Maximum Input Level::
Mic Input: -11.5 dBu; Balanced line input: + 19 dBu; Unbalanced Inputs: + 9 dBV (+15.5 dBV, one input); (for 1% THD+N at output)
Phantom Voltage::
24 Vdc (IEC 1938: 1996-12), switch-selectable for the mic input
Ducking/Muting Actuation::
Automatic (Input 1 VOX: rear-panel adjustable signal threshold with LED indicator) or Manual (contact closure to ground)
Ducking/Muting Release Delay::
4 seconds, nominal
Ducking/Muting::
Switch-selectable for inputs 2 and/or 3, 25 dB ducking attenuation, nominal
External RDL Module Power Output::
24 Vdc, 100 mA maximum, ground-referenced
Input Level::
(to cross compressor threshold equaling 23 W amplified output) Mic Input: -50 dBu (2.5 mV), (front panel gain at Balanced line input: -21 dBu (70 mV), (front panel gain at max.)
Noise (line output)::
Mic input: -68 dB, Balanced line input: -72 dB (below compressor threshold at max gain); Unbalanced Inputs: <-85 dB (max gain)
Noise (amplified outputs)::
Mic input: -68 dB, Balanced line input: -72 dB (below compressor threshold at max gain); Unbalanced Inputs: <-75 dB (max gain)
THD+N::
< 0.5% (1 kHz at compressor threshold, main amp output); < 0.25% (line output, main)
CMRR: Mic input::
> 50 dB (50 Hz to 120 Hz); Balanced line input: > 80 dB (50 Hz to 120 Hz, transformer-coupled input)
Compressor::
Threshold 2 dB below rated output, automatically adjusting attack and release times
Frequency Response (mixer)::
Mic to line output: ±1.5 dB (40 Hz to 25 kHz); Balanced line input to line output: ±1 dB (20 Hz to 20 kHz); Unbalanced line input to line output: ±0.5 dB (20
Frequency Response (Zone 1 amplifier)::
Constant voltage: ±3 dB (50 Hz to 18 kHz); 4/8 Ohm: ±1 dB (50 Hz to 20 kHz)
Frequency Response (Zone 2 amplifier)::
8 Ohm: ±1.5 dB (50 Hz to 20 kHz); 600 Ohm: ±1.5 dB (30 Hz to 18 kHz)
Tone Controls::
±10 dB @ 10 kHz, ±9 dB @ 100 Hz (front-panel) with center detent