Front Panel Features
Power Switch
The black rocker switch on the right hand side of the front panel is used to switch the amplifier on and off.
The ‘up’ position is on. When the amplifier is connected to an appropriate AC power source and is
switched on, the blue power LED will illuminate. This switch will not switch DC power on or off in DC
operation. In DC operation mode, the amplifier is always on and the blue power LED will always be
illuminated.
On LED
The blue “On” LED above the power switch will illuminate when the amplifier is connected to mains
power and is switched on. In 24vdc operation the LED will always be on.
Signal LED
The green “Signal” LED located next to the ‘On’ LED indicates that the AMIS250P is receiving audio
signal via its line level input. The signal LED is a simple method to trouble-shoot installations especially in
multi amplifier projects. At a glance the signal LED will indicate that audio is reaching the amplifier.
Protect LED
A feature of the AMIS250P is high temperature protection. In most applications, the internal cooling fan
will most probably never switch on. When used with demanding speaker loads or in difficult operating
environments, the fan may regularly switch on to cool the amp down and then switch off again. This
switching on and switching off is quite normal. The “Protect” function is there to protect the amplifier from
a high temperature problems which would only occur if the fan stopped working or became clogged up. In
this very rare occurance, the protect LED will illuminate and the amplifier may shut down. The amplifier
will automatically restart once its internal temperature has fallen within “safe” limits. If the protect LED
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.
Rack Mounting
The AMIS250P is supplied with rack ears attached to allow mounting within a standard 19” equipment
rack. As is the case with almost all audio products, adequate ventilation and air flow is required. When
installing multiple AMIS250P power amplifiers within the one rack, it is recommended that at least one
rack unit of ventilation space is left between every two amplifiers. For table or shelf mounting, the rack
ears can be removed using a screwdriver. Once the rack ears are removed, please reinstall the screws.