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GENERAL The DF1404 professional digital four-channel amplifier is designed for high MkII fidelity amplification of sound signals within a professional sound reproduction system. The amplifier can be operated in a four-channel mode, three-channel mode (one pair of channels bridged) or two-channel mode (both pairs of channels bridged). To ensure the most advantageous and faultless operation of the amplifier, please, read this Manual before use.
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AVIS RISQUE DE CHOC ELECTRIQUE NE PAS OUVRIR CAUTION! The amplifier runs on 230V AC voltage. Removing the cover will expose you to a potentially dangerous voltage! Do not use the unit if the electrical power cord is frayed or broken. Power is supplied from 230 V AC single-phase grounded 50/60 Hz source! CAUTION! The amplifier can yield dangerous output voltage! Do not touch the non-...
DESIGN FEATURES Physical Design The amplifier is enclosed in a metal (steel) case of 88 mm (2U) height. The amplifier is designed to be standard rack-mounted (RACK 19"). Physically, the amplifier consists of: • power supply unit; • four digital amplifying units installed on a common heat sink; •...
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thus making it possible to increase the power applied to the LF speaker without any danger of its overheating. The power of the amplifier is not wasted for cone flapping and allows the loudspeaker to achieve higher sound pressure. When it is necessary to achieve a linear frequency response to drive full-range loudspeakers generally used in studios or in cinema theatres, the input filter can be disabled (bypassed for each channel individually) with the slide switches located on the amplifier rear panel.
FUNCTIONAL FEATURES Overload and Short-Circuit Protection Individual per each channel. This protective system becomes active in case of short- circuited output or overload caused by reduced load impedance. It disables the output signal of the respective channel for 0.5 second and then the amplifier gradually resumes its delivery.
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As soon as the amplifier cools down, the affected channels gradually regain their amplification level up to the set value. Soft Signal Start During the power-on process, this feature ensures smooth gain from zero to the maximum level to provide for a smooth rise of the sound level emitted from the loudspeakers.
FRONT PANEL THERMAL – overheating alarm LED. Brightness depends on the temperature of the heat sink (See: Thermal Protection). POWER LED. When the DC output protection system becomes active it goes off irrespective of electric power applied to the amplifier. CLIP - overload alarm LEDs for Channels 1, 2, 3 and 4, respectively.
REAR PANEL PROFESSIONAL POWER AMPLIFIER 230V 50/60Hz 1600VA max Serial No 41441010A000 THROUGH – line outputs for Channels 4, 3, 2 & 1, respectively (XLR male). Are used to deliver input signal along the respective channel to the input of another amplifier.
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OUTPUT – output SPEAKONs for Channels 1, 2, 3 and 4, respectively, used to connect to loudspeakers. To connect loudspeakers to Channels 1 & 2 and 3 & 4 functioning in the BRIDGE mode, use outputs for Channels 1 and 3, respectively. In addition, Channel 1 output connector is interlinked with Channel 2 output, while Channel 3 output connector with Channel 4 output, thus making it possible to use a single NL4FC connector (wired accordingly) to connect Channel 1 and 2...
CABLE REQUIREMENTS Input Cables Make sure to use only shielded cables whether balanced or unbalanced. Shielding when properly grounded protects a signal against external electrical interference. As a rule, unbalanced lines over 3 meters long are not acceptable. Greater distances require a balanced cable.
RACK-MOUNTING REQUIREMENTS The amplifier is designed to fit a standard 19” rack. While mounting, make sure to provide unhindered air access to the front and rear sides of the rack. Fan direction is from front to back. It is not necessary to leave empty space above or below the amplifier. For stationary use, it will be enough to fix securely only the front panel of the amplifier to the rack.
INPUT AND OUTPUT CONNECTORS Input Connectors Use XLR (male) connectors to connect to the amplifier inputs and XLR (female) connectors to line outputs. See the wiring on the figures below. XLR female XLR male Cold (–) Cold (–) Shield (Ground) Hot (+) Hot (+) Shield (Ground)
OPERATING MODES Four-Channel Mode for Four Individual Signal Sources STEREO mode is used for both pairs of the channels. To Input Signal Sources MODE CH 3-4 MODE CH 1-2 switch is set to switch is set to STEREO STEREO PROFESSIONAL POWER AMPLIFIER 230V 50/60Hz 1600VA max Serial No 41441010A000 To Speaker Systems...
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Four-Channel Mode for Two Signal Sources MONO mode is used for both pairs of the channels. To Input Signal Sources MODE CH 3-4 MODE CH 1-2 switch is set to switch is set to MONO MONO PROFESSIONAL POWER AMPLIFIER 230V 50/60Hz 1600VA max Serial No 41441010A000 To Speaker Systems Apply an input signal to the inputs of Channels 1 and 3.
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Two-Channel Mode Both pairs of channels are bridged. To Input Signal Sources MODE CH 3-4 MODE CH 1-2 switch is set to switch is set to BRIDGE BRIDGE PROFESSIONAL POWER AMPLIFIER 230V 50/60Hz 1600VA max Serial No 41441009A000 To Speaker Systems Apply an input signal to the inputs of Channels 1and 3.
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Three-Channel Mode (Option 1) Using the bridge mode for one pair of channels and the individual mode for the other.* To Input Signal Sources MODE CH 1-2 MODE CH 3-4 switch is set to switch is set to STEREO BRIDGE PROFESSIONAL POWER AMPLIFIER 230V 50/60Hz 1600VA max Serial No 41441010A000...
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Three-Channel Mode (Option 2) Using the bridge mode for one pair of channels and the individual mode for the other.* To Input Signal Sources MODE CH 3-4 MODE CH 1-2 switch is set to switch is set to MONO BRIDGE PROFESSIONAL POWER AMPLIFIER 230V 50/60Hz 1600VA max Serial No 41441010A000...
TROUBLESHOOTING No Sound Signal on the Amplifier’s Output POWER LED is OFF: – damaged power cable; – no power; – DC protection mode. But for POWER LED all other LEDs are OFF: – no input signal; – input level attenuators are set to minimum position. SIGNAL and CLIP LEDs are occasionally blinking: –...