Peavey DPC 1400X - Manual (Page 6)

status LEDs will be illuminated green. In any event, corrective action should be taken to determine
the cause of the thermal shutdown. If the amplifier is not severely overloaded or shorted and air flow
is normal in and out of the amplifier, then steps should be taken to provide a cooler environment for
all the amplifiers. As a general rule, the cooler electronic equipment is operated, the longer its useful
service life.
STUDIO AND FACILITY INSTALLATION
In most low to medium power applications, the power amplifier can be mounted in any configuration.
It is desirable that, if at all possible, the power amplifier be located at the top of an equipment stack.
This will prevent possible overheating of sensitive equipment by the hot air rising from the power
amplifier. As a general rule, most studio requirements will never cause high speed fan operation.
However, if they do, this may indicate that you have not taken the necessary steps to provide
adequate cooling. Remember, closed up in a cabinet, a DPC Series power amplifier will have severe
cooling problems, even at low power levels. Again, inadvertent short circuit or sustained overload
usage could also cause temporary thermal shutdown and/or blowing of the fuse. Also, most home
wiring and electrical circuits are only 15 amps.
BRIDGE MODE
The bridge mode on stereo amplifiers is often misunderstood as to the actual operation and usage.
In basic terms, when a two-channel amplifier is operated in the bridge mode, it is converted into a
single-channel unit with a power rating equal to the sum of both channels’ power ratings at a Load
Rating of twice that of the single channel rating. For example, the DPC 1400X is rated at 700 watts
RMS per channel into 2 ohms. The bridge ratings are 1,400 watts RMS into 4 ohms (minimum load).
Bridge mode operation is accomplished by placing the mode switch in the “BRIDGE” position,
connecting the positive speaker lead to Channel A red binding post, negative speaker lead to
Channel B red binding post, and using Channel A as the input channel. All Channel B input functions
are defeated, and they serve no purpose now. Another common use for the bridge mode is in
subwoofer applications where very high power levels are required to reproduce extreme low
frequencies. Such enclosures usually contain 2 or 4 loudspeakers to handle the power levels
involved. For bridge mode usage, the enclosure impedance must be 4 or 8 ohms—never below
4 ohms!
DDT ™
Peavey’s patented DDT (Distortion Detection Technique) compression circuit enables the user to
maximize the performance of the amplifier/speaker combination by preventing the power amp from
running out of headroom (clipping). This compression system is activated by a very unique circuit
that senses signal conditions which might overload the amplifier and activates compression (reduces
the amp gain) when clipping is imminent. Threshold of compression, then, is clipping itself, and no
specific threshold control is used. This technique effectively utilizes every precious watt available for
the power amplifier to reproduce the signal, while at the same time minimizing clipping and distortion
and thus significantly reducing the potential of loudspeaker degradation and damage. The DDT
system is an automatic hands-off approach to the problem of power amplifier clipping. Since the
DPC Series power amplifiers use a fuse for “over current” protection, the DDT compression system
plays even a more important role in continuous performance by preventing each channel from
clipping and overload. Continuous operation at clipping can cause the fuse to blow, but with the DDT
activated, this problem is minimized. For this reason, you should always have the DDT compression
system enabled.
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