Crown CT 475 User Manual

8 Amp Configuration

9 Operating Modes

8.1 70Hz HPF (High Pass Filter) 
On the back panel, one 2-position high-pass filter 

switch will only allow signals above 70Hz to be 

amplified. This is to prevent transformer saturation. 

The HPF, when turned on, is activated for all channels. 

The filter is a 2nd order 12 dB/occ t filter. 

8.2 Limiter
The limiter reduces amplifier gain to allow over drive 

without harsh clipping at output.
When Amp Configuration Switch #5 is set to on 

(pushed up), the amplifier will utilize the limiter feature.

DriveCore Amplifiers can work in a variety of          
power modes.

9.1 Normal
The amplifier automaticaly operates full output power.

9.2 Green Power
Green mode utilizes Crown’s adaptive rail technology 

for higher efficiency or power on demand.  When Amp 

Configuration DIP switch #4 is set to on, the amplifier 

will operate in green mode.
For low input signal levels (less than –40dBu) the 

amplifier will operate with minimum power.  
The amplifier will increase to full power if either of the 

following occurs:
1 - The input signal goes above -40dBu
2 - There is a single clip event from any of the channels
Likewise, if the amplifier is operating with full power, 

the amplifier will decrease the operating rails to 

minimum power if the input signal drops                  

below -40dBu.
Through the use of Green Power, the efficiency of the 

amplifier dramatically increases for lower audio signal 

reproduction. The adaptive rail technology used in the 

CT amplifiers can increase the efficiency of the 

amplifier by up to 10% with low signal levels.

9.3 Deep Sleep
See Section 10.1

Y

E

S

NO

NO

Y

E

S

Full Power

Minimum Power

Is green mode 

DIP switch on?

Lower voltage rails 

Increase rails to Full Power

Is there a clip

event?