Crest Audio CPX 3800 - Manual (Page 26)

turn-on/turn-off protection
At power-up, the amplifier stays in the protect mode with outputs disconnected for approximately six
seconds while the power supplies charge and stabilize. While the output relays are open, the GCL™ LEDs
light. When power is removed, the speaker loads immediately disconnect so that no thumps or pops are
heard.
AUTORAMP ™ signal control
Whenever a CPX Series amplifier powers up or comes out of a protect mode, the AUTORAMP circuit acti-
vates. While the speakers are disconnected, the AUTORAMP circuit fully attenuates the signal and activates
the GCL LED. After the output relay closes, the signal slowly and gradually raises to its set level. The PWR
LED will illuminate and the GCL LED will turn off when the signal is no longer attenuated. The AUTORAMP
Signal Control circuit has some important advantages over conventional instant-on circuits:
1. If a signal is present during power-up (or when coming out of protect), the speakers are
spared a sudden, potentially damaging burst of audio power.
2. Because the gain is reduced until after the output relay closes, no arcing occurs at the
contacts. This extends the contacts’ useful life.
p. 26
protection features 5
CPX TM owner’s manual