Other Features
Tone Generators
Four separate tones are available from the in-built tone generator board. All four tones can be activated individually via
a contact closure connected to the screw terminals on the rear of the amplifier. To activate the bell chime for example, just
run a pair of wires from the Tone generator common and the Bell terminal to an external switch. Activating the switch, or
closing the pair of wires, will activate the bell. When any tone is activated, all inputs (except for inputs one and two) will
automatically mute. To adjust the level of the tone generator, disconnect the power lead, remove the amplifier lid and
locate the pot labeled R6. (located behind the Bass adjustment pot). This pot adjusts the level for all 4 tones.
Tones available on the ACM60 and ACM120 include:
- Evacuation Tone (to Australian Standard AS2220.1.2)
- Alert Tone (to Australian Standard AS2220.1.2)
- Bell Tone
- Pre-Announce Chime
Muting
A VOX muting card is installed in the ACM60 and ACM120. This feature provides automatic muting of some channels
when others are active. It is normally used so that a paging microphone can have priority (by muting) over background
music. VOX muting is available from channels 1 and 2 meaning that any signal on channels 1 and 2 (mic or line) will mute
channels 3 & 4. The muted channels will automatically ramp back up to normal volume when the signal on channels 1
and/or 2 is no longer active. The amplifier ships with the VOX muting function enabled. To disable the VOX muting,
disconnect the mains power lead and remove the lid of the amplifier. Looking down from the front of the amplifier, a three
position jumper (labeled JP2) is located just to the left and behind the level pot for channel 1. To disable VOX muting,
move the jumper to the middle and left pins. (Factory setting is with VOX enabled with the jumper on the middle and right
pins).
Fuse Sizes
Mains ACM60, 240 VAC: 2 Amperes Slow Blow
Mains ACM120, 240 VAC: 4 Amperes Slow Blow
Notes
The DC fuse is located on the circuit board. This is a feature of the ACM series amplifiers, which are equipped with a
current limiting circuit preventing excessive DC currents, thus eliminating the risk of blowing high tension 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.