Protection Features; Thermal Protection; Short Circuit; Dc Voltage Protection - Peavey CS 6000 Operating Manual

Protection Features

The CS 6000/ CS 4000 amplifier incorporates several circuits to protect both themselves and loudspeakers under vir-
tually any situation. Peavey has attempted to make the amplifiers as foolproof as possible by making them immune to
short and open circuits, mismatched loads, DC voltage, and overheating. If a channel goes into the Distortion Detection
Technique or DDT™ gain reduction mode, the speaker load remains connected, but clipping percentage is instantly
reduced. DC voltage on the output, excessive subsonic frequencies or thermal overload will cause the channel' s output
to disconnect from the speaker load until the problem is corrected or the amplifier cools down.
Distortion Detection Technique™ (DDT)
Any time a channel is driven into hard, continuous clipping, the DDT circuit will automatically reduce the channel
gain to a level just slightly into clipping, guarding the speakers against the damaging high power continuous square
waves that may be produced. Situations that may activate the DDT circuit include uncontrolled feedback, oscillation, an
improper equipment setting or malfunction upstream from the amplifier. Normal program transients will not trigger
the DDT, only steady, excessive clipping will. The DDT LED will flash on peaks when DDT is active, and will flash
brightly with clipping when DDT is disabled.

Thermal Protection

Internal fans keep the amplifier operating well within its intended temperature range under all normal conditions. If the
amplifier temperature rises above its normal operating range, thermal protection circuitry reduces the output power on
that channel until it is safe to return to normal operation. During this time, the THERMAL PROTECT LED will light
up and the fans will continue to run at high speed.

Short Circuit

If an output is shorted, the overcurrent protection circuit will engage and reduce the output of the amplifier to protect
the output devices. Solid red DDT LEDs and dim signal LEDS is an indication of a short circuit and should be
investigated immediately. To find the cause of the overload, start by disconnecting one output at a time, and then one
speaker at a time until the bad cable or damaged speaker is isolated.

DC Voltage Protection

If a DC or subsonic voltage is present at the outputs, a crowbar circuit engages to prevent loudspeaker damage.
9