Overview
The RMA400 contains four discreet microphone amplifiers with analogue, AES and
HD-SDI embedded outputs. The unit may be controlled locally using the front panel
controls and display or it may be controlled over ethernet.
Gain range of the microphone amplifiers is 0-66dB in 1dB steps. The unit has built in
limiters, switchable 48 volt phantom power, 10dB pads and high pass filters.
All channels include their own metering and the microphone outputs may be
monitored locally on headphones.
Power
The unit requires a 12 volt DC supply. Either connect the supplied adaptor to the
power inlet or a 12 volt battery. Pin 1 is ground and pin 4 is +12V.
The display will show channel 1 settings and all gains, limit levels and button settings
will have been memorised from power down.
Local controls
On power up the unit’s controls will be ‘locked’. In this situation the Mon/Select
buttons will operate to display gain and limiter settings and to allow monitoring of
the outputs on headphones. Pressing any other button will show ‘Locked’ on the
display.
Press the two centre HPF buttons for approximately 3 seconds and the unit will
display ‘Unlocked’. Settings may now be changed as required.
A single press on the Mon/Sel button will display the gain and limiter settings for
that channel. Press the button again and ‘Micx’ will be highlighted. Now press the +
and – buttons to adjust gain as required. Gain range is 0dB to +66dB.
Press the Mon/Sel button again and ‘Limx’ will be highlighted. Adjust the setting as
required using the +- buttons. Note that the limit level is in dBFS so the range is -18
to 0 dBFS. Press the Mon/Sel button again to return to normal.
All other buttons just toggle of and off when pressed. Phantom power is standard 48
volts, the 10dB pad helps prevent microphone overload in high SPL applications.
The High Pass Filter is 6dB down at 100Hz and is suitable for prevention of wind
noise.
To lock the buttons again press the two ‘unlock’ buttons again. The display will show
‘Locked’ until the buttons are released.
Headphone Monitoring
The headphone output will follow any input as selected by the Mon/Sel button. This
facility is intended for confidence monitoring and has no volume control.
