R a d i o S y s t e m s , I n c .
M A - 4 M a n u a l
P a g e 3
Apply a sine wave test signal to any one left input. Connect an AC voltmeter (with audio
frequency response) or oscilloscope to the left channel output test point. Set the input’s left
channel front panel mix-bus attenuator for an output level using the following formula:
output voltage of a single input
=
desired total output voltage
number of active inputs
For example, if the desired output voltage is 2.18 Vpp (0dBm), and there are 4 active inputs per
channel, then the output voltage of any single input should be 0.545 Vpp.
Disconnect this input and repeat for all additional inputs you will be connecting. Repeat the
procedure for the right channel inputs.
Next, connect and simultaneously apply sign wave from all inputs. Check that the output now
equals the desired total output voltage. Use the individual channel test points to check, tweak
and match each input level.
The unit is now ready for unattended, full-time operation. Use the headphone output to
monitor mixed output material. Do not use phones of less than 2K ohms impedance.
