Rear Panel Features
AC Power Inlet
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. Before plugging in a power lead, please check the rear panel of the amplifier to ensure that the
voltage label shows the correct AC operating voltage for your part of the world. The inlet is equipped with an in-built AC
fuse holder fitted with a 5 Amp slow blow fuse plus a spare fuse. Please ensure that the mains power cord is discon-
nected before attempting to check or replace this fuse. Power consumption is 400 watts (max).
Mic/Line Input Terminal Strip
Located on the top half of the rear panel are the input connections for all 4 amplifiers. Each amplifier will accept balanced
microphone or line inputs (selectable via an internal dip switch). Additionally, a remote pot can be connected to each
amplifier for external control of the master level.
The rear panel is split into four sections, one for each amplifier. Looking at the back panel and reading from left to right
the amplifiers are 4, 3, 2 and 1. In other words, the input and output section is directly behind the relevant front panel
controls.
The inputs are labelled Ch1, Ch2 and Ch3. All are balanced with the connection reading left to right as “Ground, +
positive, - negative”. Each input can be switched to be either mic or line level via a dip switch behind each input and
accessible through the top lid. Additionally, phantom power (+18v DC) is selectable per input. The dip switch settings
are:
Balanced Mic Level - 1 and 2 On
Balanced Line Level - 1 and 2 Off
Phantom Power (+18v) - 3 ‘On’ to enable phantom power or ‘Off’ to disable phantom power
VCA Remote Master Level Control
Located on the right side of each input terminal strip is a two position screw terminal block for an external pot. For remote
master level control, an external 500-1K ohm pot can be connected per amplifier.
Speaker Output Terminal Strip
Located on the bottom half of the back panel is the speaker output terminal strip. Four separate speaker output terminal
strips are provided, one for each amplifier. Looking at the back panel and reading from left to right the amplifiers are 4, 3,
2 and 1. In other words, the speaker output section is directly behind the relevant front panel controls.
Each of the four amplifiers in the ACM604 can work with 8 ohm and/or 70/100 volt line speakers systems.
Rack Mounting
The ACM604 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 ACM amplifiers
within the one rack, it is recommended that at least 1 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.