TOA M-61F Mic Input Module with Compressor, Female XLR, 900 Series

Hand a wireless microphone to a guest speaker and the level is anybody's guess. The TOA M-61F exists for exactly that problem. It is a 900 Series microphone input module built around the same transformer-balanced 600-ohm front end and female XLR jack as TOA's standard mic modules, with a built-in compressor added on board. Once the input signal crosses an adjustable threshold the module clamps down at a fixed 2:1 ratio - every 2 dB of extra input yields only 1 dB more output - so loud talkers, plosives and handling noise stop driving the amplifier into overload and distortion.

The threshold is set with a screwdriver trim at commissioning: turning it clockwise lowers the threshold so compression starts earlier on quieter signals, counter-clockwise raises it so only genuinely hot inputs are caught. The adjustable threshold range spans -66 to -46 dB, with a specified signal muting level of 20 dB. Alongside the compressor sit the fixed low- and high-cut filters at 330 Hz and 4.2 kHz, both at 6 dB per octave, which trim HVAC rumble and harshness before they reach the mix bus. Phantom power at +22 V DC is active by default for condenser microphones and is disabled by cutting jumper J1 on the module.

The M-61F installs like every other 900 Series card: it seats in any of the eight input ports on the A-903MK2, A-906MK2 and A-912MK2 mixer power amplifiers or the M-900MK2 mixer preamplifier, in the W-906A and W-912A in-wall mixer power amplifiers, in the two 900 Series module slots of the 800D Series digital mixer amplifiers A-812D, A-824D and A-848D, and in TOA's 9000M2 Series amplifiers, which accept existing 900 Series input modules. It draws 33 mA from the host frame's 24 V DC rail. Specify the M-61F for lecterns, courtrooms, council chambers, gymnasiums and any paging microphone the public will actually touch.

Features

• Microphone input module with on-board compressor for TOA 900 Series mixer/amplifiers
• Compressor prevents overload and distortion when input exceeds a preset threshold
• Fixed 2:1 compression ratio - output rises 1 dB for every 2 dB of input increase
• Adjustable threshold control sets when compression engages
• High-cut and low-cut filters at 4.2 kHz and 330 Hz, 6 dB/octave
• +22 V DC phantom power active by default; disabled by cutting jumper J1
• Transformer-isolated 600-ohm balanced input on a female XLR connector
• Fits A-903MK2, A-906MK2, A-912MK2, M-900MK2, W-906A, W-912A, the 900 Series module slots on the A-812D / A-824D / A-848D, and 9000M2 Series amplifiers

Technical Specifications

• Module type: Balanced microphone input module with compressor (900 Series)
• Power supply: 24 V DC (supplied from the main frame)
• Current consumption: 33 mA
• Input sensitivity: -60 dB (0 dB = 1 V), rated output -20 dB; adjustable -72 to -52 dB
• Input impedance: 600 ohms, balanced, transformer-isolated
• Frequency response: 25 Hz - 20 kHz, ±1.5 dB
• Distortion: 0.1% or less (1 kHz, output -60 dB)
• Noise level: -86 dB (20 Hz - 20 kHz BPF); input-equivalent noise -126 dB
• Gain: 32 - 52 dB
• Tone control: 100 Hz, 0 to -10 dB; 10 kHz, 0 to -10 dB
• Compression ratio: 2:1 (fixed)
• Signal muting level: 20 dB (threshold-adjustable input level -66 to -46 dB)
• Phantom power: +22 V DC (for condenser-type microphones)
• Connector: Female XLR (XLR-3-31 equivalent)
• Module dimensions: 35 (W) x 78 (H) x 88 (D) mm / 1.38" x 3.07" x 3.46"
• Module weight: Max. 110 g (0.24 lb)
• Shipping weight: 0.2646 lb
• Shipping carton: 3.54" x 3.74" x 1.57"

What's Included

• 1x TOA M-61F microphone input module with compressor and female XLR connector
• No additional accessories are specified by TOA for this module