8
2 ohm & Bridged LEDs
These indicate the position of the switches on the rear panel. The 2 ohm LED will also illuminate if the
controller senses a low impedance load (excessive temperature rise).
INTERNAL CONFIGURATION SWITCHES
As these can only be accessed by removing the top panel
this should only be carried out by qualified
personnel.
The control PCB is located on the side of the unit behind the front panel. The switches are an 8 switch
DIL package at the rear of the PCB. For full description of the switches consult the Service manual.
The standard configuration is for all switches to be ON, except Sw2 and Sw6, which are normally OFF.
Sw 1
Temp LED operation. ON = Standard position, OFF = alternative position. (See
temperature control section above.)
Sw 2
(Normally OFF) This selects the auto reconnect mode. If switched OFF when a fault has
been detected, the amplifier will not reconnect the outputs even when the fault is cleared.
This is a safety requirement in certain applications.
Sw 3
(Normally ON) When OFF the LED columns will always show the signal level and will
not change to show the level control position when the level controls are adjusted.
Sw 4 & 5 These select the threshold level as follows:-
Sw4 Sw5
ON ON
Just below clipping point.
ON OFF
1dB below clipping point.
OFF ON
2dB below clipping point.
OFF OFF
3dB below clipping point.
Sw 6 & Sw 7 operate together, they determine the operating mode and release time of the limiter as
follows:-
Sw6
Sw7
Function
OFF
OFF
Release time = slow
OFF
ON
Release time = fast
ON
OFF
Automatic Gain Control mode. (Once the level has
been reduced it will emain at that level until changed
manually).
ON
ON
Limiter disabled.
Sw 8 (Normally ON) This sets the attack time of the limiter. ON = Fast
OFF = Slow
FAULTS/FUSES
There are internal secondary (low voltage) fuses on all the internal supply rails. If one of them blows the
amplifier will indicate a fault on both channels and the unit will power down. If the controller (5 volt)
supply fails all LEDs will go out and the unit will shut down.
The unit must be disconnected from the mains supply, and the fuses replaced before switching the unit
back on. They should be replaced with the same type fuses only.
THIS SHOULD BE CARRIED OUT BY QUALIFIED PERSONS ONLY.
