illuminates, it is best to switch the amplifier off, let it cool down and then try it again. If the protect LED
illuminates again, please contact the company who supplied or installed the equipment.
Rear Panel Features
AC Power Inlet
The operating voltage is 115 VAC @ 60 Hz. The 3 pin IEC power inlet is located on the bottom left of the
rear panel and accepts a standard mains power lead fitted with an IEC connector.
The inlet is equipped with an in-built AC fuse holder fitted with an 8 amp fuse plus a spare within the
holder. Power consumption is 550VA.
Please ensure that the mains power cord is disconnected before attempting to check or
replace this fuse.
24 Volt DC Power Inlet
The AMIS250 features optional 24VDC power to run off a battery supply if required. This is connected via
the rear terminal strip. The front panel Power Switch will not switch DC power ‘on’ or ‘off’ in DC
operation. In this mode the amplifier is always ‘on’.
Speaker Output Terminal Strip
The screw terminals on the left hand side of the strip allow access to the direct speaker outputs of the
amplifier. The screw terminals on the right hand side are for activation of the in-built 4 tone generator.
Reading from left to right the terminals are:
Low Impedance Common
(use with 4 ohms)
4 Ohms
Spare
Constant Voltage Common
(use with 25v or 70v)
25 Volt Line
70 Volt Line
Spare
Tone Generator Common
(use with one of the 4 tones listed below)
Pre-Announce Chime
Alert Tone
Bell Chime
Evacuation Tone
Note:
The minimum impedance (or maximum load) at 70 Volt line should be no less than 20 Ohms.
Phantom Power
This button enables or disables the 18 volts DC phantom power which is available on all microphone inputs
(XLR’s). The “in” position indicates that phantom power is on for all mics. The “out” position means that
phantom power is switched off for all mics. Phantom power is required for electret condenser microphones
which require DC power to operate. While some of these microphones can operate from an internal battery,
having phantom power available on the amplifier eliminates the need to regularly change batteries in the
