Protection Features - Peavey CS 1400 Manual Del Usuario

Protection Features

The Peavey CS Series incorporates several circuits to protect the amplifier and speakers under virtually any situation. Peavey
has made 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 DDT
percentage or output power is instantly reduced. When a problem occurs that causes a channel to go into a protection mode,
the PWR (Power) LED for that channel will turn off. DC voltage on the output or excessive subsonic frequencies will cause the
triac crowbar circuit to activate to protect the speakers. If the amplifier overheats, the signal will be removed from the channel
that is at fault until the amplifier cools down, thus protecting the amplifier.
Distortion Detection Technique (DDT) Limiting
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, oscillations,
an improper equipment setting or malfunction upstream from the amplifier. Normal program transients will not trigger
DDT; only steady, excessive clipping will cause the DDT LED to illuminate.
LFC Impedance Sensing
CS Series amplifiers feature innovative circuitry for safe operation into any load. When an amplifier senses a load that
overstresses the output stage, the Load Fault Correction circuit adjusts the channel gain to a safe level. Extreme load
fault under high power levels will cause the signal to be muted for the associated channel. This method of output-
stage protection is far more effective than the standard limiting found on conventional power amplifiers. The LFC
circuit is sonically transparent in normal use and unobtrusive when activated.
Thermal Protection
The internal fans will keep the amplifier operating well within its intended temperature range under all normal
conditions. If a channel's heat sink temperature reaches 85° C (which may indicate an obstructed air supply), that
channel will independently protect itself by muting its input signal and shut down until it has cooled. During this time,
the PWR LED will go out and the cooling fans will continue operating at high speed.
Short Circuit
If an output is shorted, the LFC and thermal circuits will automatically protect the amplifier. The LFC circuit senses
the short circuit as an extremely stressful load condition and attenuates the signal, protecting the channel's output
transistors from over-current stress. If the short circuit remains, the channel will eventually thermally protect itself by
muting the input signal.
DC Voltage Protection
If an amplifier channel detects DC voltage or subsonic frequencies at its output terminals, the output triac crowbar
circuitry will activate immediately to prevent speaker damage.
Turn-On/Turn-Off Protection
Upon powering up, the amplifier stays in Protect mode, muting the input signal for approximately four seconds while
the power supplies charge and stabilize. Also, when power is removed, the input signals are muted so that no thumps
or pops are heard.
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gain reduction mode, the DDT LED illuminates. The clipping
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