AUDIO TELEX IC30, Service Information, Page: 2 / 14

IC30
Circuit Description
The IC30 is a 30 watt mixer amplifier which operates on 230/240 VAC, 50Hz or 12 VDC via an external
DC power supply source. The amplifier is supplied free standing with rubber feet but can be rack mounted
via an optional rack mount kit (IC30RMK). The IC30 will deliver 30 watts into a load of 4 ohms, 70 volt or
100 volt line. The IC30 may be stacked to a maximum of four units high. An IEC type mains cord and
receptacle are provided, the receptacle also houses the mains fuse in a drawer which pulls open to expose
the fuse. A single spare fuse is also located in this drawer.
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 switch is set correctly for your part of the world.
The operating voltage is 230/240 VAC @ 50 Hz. The inlet is equipped with an inbuilt AC fuse holder fitted
with a 1 amp plus a spare within the holder].
Power consumption is approximately 60 VA.
12 Volt DC Operation
The IC30 features optional 12VDC 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’. When running from 12 VDC power, the LED will not illuminate.
There is no trickle charge resistor across the diode.
230V/240V Slide Switch
The operating voltage of the amplifier is user selectable between 230V and 240V via a slide switch located
on the top left side of the rear panel. This switch should be set to match the AC voltage of your country.
The mains transformer is wound with a 230V winding plus a 10V winding internally connected.
Power Amp
The IC30 uses two(2) Philips amplifier ICs (TDA1516) with built in current overload and thermal
protection. The two amplifier modules are capacitively coupled to the two primary windings of the output
transformer in parallel (not in bridge).
Speaker Output Terminal Strip
The screw terminals in the middle of the strip allow access to the direct speaker outputs of the amplifier.
Reading from left to right the terminals are:
COM Common or “-” for low impedance speaker loads (4 or 8 ohms).
4 Positive “+” for 4 ohm speaker loads (use with common)
COM Common or “-” for 70v or100v speaker loads (maximum load of 80 ohms at 100v)
70 Positive “+” for 70v line speaker loads (use with common)
100 Positive “+” for 100v line speaker loads (use with common)
Please ensure that the correct “Common” is used. Low impedance and 70/100v loads can be used
simultaneously but please pay careful attention to the overall speaker load.
Note: The minimum impedance (or maximum load) at 100 volt line should be no less than 80 Ohms