AUSTRALIAN MONITOR AMIS120 Series, Service Manual, Page: 4 / 26

[600 Ohm Telephone Input] (115V version)
Switched Speaker System
Speaker (Zone) Output Terminal Strip
Reading from left to right, these screw terminal pairs correspond to the switched line voltage outputs and
are numbered 6 through 1 as indicated on the front panel of the amplifier. For each pair, the left hand
terminal is the line voltage output and the right hand terminal is the common.
All Call Button
When pressed, the All Call button will connect the line voltage output of the amplifier to all 6 of the
switched outputs.
Speaker (Zone) Selector Switches
These 6 black buttons are for switching the line voltage output of the amplifier to any combination of the 6
available speaker zones. The maximum capacity of each speaker zone is 60 watts so care should be taken to
ensure that no individual zone is loaded down with any more than 60 watts, always remembering that the
total load for the AMIS60 is 60 watts and for the AMIS120, 120 watts in total. Eg: it is possible on the
AMIS120 to safely have one zone loaded with 60 watts and the remaining five loaded with 12 watts each.
All switches are latching and non-interlocking.
Phantom Power Button
This button enables or disables the 15 volts DC phantom power to all microphone XLRs. Do not plug an
unbalanced microphone in to any amplifier or mixer when phantom power is switched ‘on’.
The phantom voltage is connected through 4k7 1/4W resistors. The maximum current draw available per
microphone is approximately 3mA.
Line Output
The balanced XLR line level output provides a maximum of 700mV to allow for the connection of up to 6
power amplifiers. Pin connections are: pin 1-earth; pin 2-signal (hot +); pin 3-signal (cold -).
The output is electronically balanced with an inverting op-amp and buffered with voltage follower op
amps. Neither hot nor cold output should be grounded when connecting as unbalanced.
Tape Output
Dual RCA output connectors provide a line level output with a maximum of 350mV into 10k Ohms. This
output is sourced before the master gain control so the tape output level is not influenced by the operation
of the master gain control.
Microphone Inputs
All four inputs are dual mic/line with microphone inputs being via a 3 pin XLR connector per channel. The
mic input sensitivity is 1mV @ 200 ohms. Pin connections are: pin 1-earth; pin 2-signal (hot +); pin 3-
signal (cold -). Phantom power of +15 volts is available on all microphone inputs. Reading from left to
right across the rear panel, the inputs are 4, 3, 2, & 1.
Line Inputs