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 AMIS604 can work with 8 ohm and/or 25/70 volt line speakers systems.
The various outputs are marked as follows:
COM
Common or “-” for low impedance speaker loads (8 ohms).
8
Positive “+” for 8 ohm speaker loads (use with common)
COM
Common or “-” for 25v or 70v speaker loads (maximum load of 80 ohms at 70v)
25
Positive “+” for 25v line speaker loads (use with common)
70
Positive “+” for 70v line speaker loads (use with common)
Please ensure that the correct “Common” is used. Low impedance and 25/70v loads can be used
simultaneously but please pay careful attention to the overall speaker load. When used individually, the low
impedance load should be 8 ohms or higher while the 70v line load should not fall below 80 ohms. When
both outputs are used simultaneously, ensure that neither output is loaded to maximum.
VOX Muting
The AMIS604 includes a VOX muting circuit which is independent for each amplifier. The unit is factory
set so that input 1 of each amplifier has VOX priority over inputs 2 and 3 for that amplifier. Basically,
when signal is present on input 1, audio from inputs 2 and 3 is muted. As mentioned, each amplifier is
totally independent so the VOX circuit from one amplifier does not affect any of the other amplifiers.
Muting can be defeated per amplifier via an internal jumper labelled JP2 (located on the top board
behind inputs 1 and 2. The AMIS604 is shipped with muting enabled (jumper towards the front
panel of the amplifier). To disable VOX muting per amplifier, simply move the relevant jumper
(from amplifiers 1, 2, 3 or 4) so that it is closest to the back panel.
Optional ATC5489 Tone Generator/Vox Relay Card
An optional Tone Generator/Vox Relay card is available for the AMIS604. Each card controls one
amplifier within the unit so up to 4 cards can be installed. The card slots in between the input terminal strip
and the output terminal strip on the rear panel of the amplifier. Simply remove the two screws and blanking
plate, slide in the ATC5489 and replace the screws. The card provides a 4 tone generator module (Pre-
Announce, Bell, Alert and Evacuate tones) per amplifier and also provides a VOX triggered relay output
per amplifier. Full installation and operation instructions are included with the ATC5489.
Fuse Sizes
Mains, 115VAC: 5 Amperes Slow Blow.
Notes:
The DC fuse is located on the circuit board. This is a feature of the AMIS series amplifier,
which is equipped with a current limiting circuit preventing excessive DC current, thus
eliminating the risk of blowing high tensions fuses. In the unlikely event that the DC fuse
actuates, the output transistors should be checked, as it is probable that the amplifier has been subjected to
very extreme conditions.
