CA 4D
|4 CHANNEL POWER AMP
CA 4D
|OPERATING INSTRUCTIONS
8 |
P a g e
POWER SUPPLY
The power supply is a state-of-the-art, heavy duty and wide-range switch mode design, with
Power-Factor- Correction (PFC) built in. The start-up voltage is limited to assure maximum
protection. A second widerange and heavy duty switch mode power supply, with PFC, is used to
independently supply the controller card electronics along with the low voltage cooling fans and,
the stand-by ON/OFF system, via the KS Audio remote digital controller system.
COOLING
In the production of high audio output levels, large amounts of heat are also generated as a side-
product of the amplifier, which could damage the semi conductors. The reduction of these high
temperatures is done with the use of 3 independent, thermal controlled cooling fans. The air is
taken in from the front panel inlet of the power amplifier and passed through to the back panel
outlet while passing over the heat fins and power transformer to actively cool these units down to
nominal operating temperatures.
PROTECTION SYSTEMS
As a KS Audio standard of operation, the input signal to the amplifier is effectively limited to
protect the drivers. On powering up the CA 4D amplifier a 20 Amp switch-on relay circuit is
engaged to ON to protect the drivers. If the DC current changes by more than 0.5 V, a special
detection circuit disconnects the speakers from the amplifier for their protection. The same
protection takes place if electrical shortage or low impedance occurs. When the cause is remedied
the circuits return to their full operational status.
If the internal heat increases above 85 C (185 F), protection is engaged to deactivate the power
amps for as long as it takes for the cooling fans to reduce the temperature to 85 C (185 F) again.
Overheat status will be indicated by a RED ERROR LED light and the power READY light is dimmed.
Also, during this protected time, information appears in the LCD display pointing out the problem.
The LCD display is only available when F MOD controller card is inserted in the amplifier.
