User manual CREST AUDIO FXA SERIES

[. . . ] FXA PROFESSIONAL POWER AMPLIFIERS CLIP -6 -6 -3 -10 -15 -1 -80 0 dB Ch A -30 -80 Ch B -1 0 dB -3 CLIP -10 -15 SIGNAL PROTECT ACTIVE SIGNAL PROTECT ACTIVE FXA OFF -30 CLIP -6 -6 -3 -10 -15 -1 -80 0 dB Ch A -30 -80 Ch B -1 0 dB -3 CLIP -10 -15 SIGNAL PROTECT ACTIVE SIGNAL PROTECT ACTIVE FXA OFF -30 CLIP -10 -6 -3 -10 -15 -1 -80 Ch A 0 dB -30 -80 -15 -6 -3 CLIP SIGNAL SIGNAL OFF PROTECT ACTIVE -30 -1 0 dB Ch B FXA PROTECT ACTIVE CLIP -10 -6 -3 -10 -15 -1 -80 Ch A 0 dB -30 -80 -15 -6 -3 CLIP SIGNAL SIGNAL OFF PROTECT ACTIVE -30 -1 0 dB Ch B FXA PROTECT ACTIVE CLIP -10 -6 -3 -10 -15 -1 -80 Ch A 0 dB -30 -80 -15 -6 -3 CLIP SIGNAL SIGNAL OFF PROTECT ACTIVE -30 -1 0 dB Ch B FXA PROTECT ACTIVE CLIP -10 -6 -3 -10 -15 -1 -80 Ch A 0 dB -30 -80 -15 -6 -3 CLIP SIGNAL SIGNAL OFF PROTECT ACTIVE -30 -1 0 dB Ch B FXA PROTECT ACTIVE OWNER' S MANUAL Important Precautions This symbol is used to alert the operator to follow important operating procedures and precautions detailed in documentation. This symbol is used to warn operators that uninsulated "dangerous voltages" are present within the equipment enclosure that may pose a risk of electric shock. 10. Power down & disconnect units from mains voltage before making connections. Never hold a power switch in the "ON" position if it won't stay there itself! [. . . ] If the power transformer overheats, another sensing circuit opens both channel output relays until the transformer cools to a safe temperature. IMPORTANT: To ensure optimum cooling, periodically clean the amplifier fan filters (removable without tools). Also make certain that there is enough space around the front of the amplifier to allow the cooling air to escape. If the amplifier is rack-mounted, do not use doors or covers on the front of the rack; the exhaust air must flow out without resistance. If the amplifiers are to be housed in racks with closed backs, allow at least one (1) standard rack space of opening in the front of the rack for every four amplifiers. Crest Audio FXA Series Power Amplifiers Models FXA601, FXA901, FXA1201, FXA2401, FXA3601, FXA4801 Page 9 FXA Connecting Inputs. Use either the XLR or 1/4-inch input connectors on the rear to supply audio signals to your Crest Audio FXA Series amplifier. Both connectors accept balanced and unbalanced audio connections. (The FXA Series amplifiers are configured standard with "Pin 2 hot" on XLR inputs. Please note that some other Crest Audio amplifiers are configured with "Pin 3 hot"). The unused connector can be used to jumper the audio input to another amplifier input. For more information, see the sections on Balanced 1/4" (TRS) & XLR Input Connectors, Input XLR Polarity, and Input Sensitivity. Speakers are connected using 5-way Output Binding Posts. Please note that on the 5-way Output Binding Post version of the FXA4801, two pairs of 5-way binding posts are provided for each channel, so that paralleling of speakers is possible. For more information, see the Output Connectors and Mode Selection sections. Mode Selection. The three-position, recessed Mode Select switch (located on the rear panel) configures the amplifier for either Stereo, Parallel or Bridged Mono Mode. Amplifiers are factory-configured for Stereo Mode. In Stereo Mode, both channels operate independently, with their input attenuators controlling their respective levels. Signal at Channel A's input produces output at Channel A's output, while signal at Channel B's input produces output at Channel B's output. Recommended minimum nominal load impedance for stereo operation is 2 ohms per channel. Either the 1/4" (TRS) inputs or the XLR inputs may be used. When set to Parallel Mode, a signal applied to Channel A's input will be amplified and appear at outputs for both Channels A & B. Either the 1/4" (TRS) input or the XLR input on Channel A may be used. Bridged Mono Mode straps both amplifier channels together to make a very powerful, single-channel monaural amplifier. [. . . ] (m) 2 0. 3 0. 5 0. 75 1. 5 2. 5 4 0. 5 0. 75 1. 5 2. 5 4 6 0. 5 0. 75 1. 5 2. 5 4 6 0. 75 1. 5 2. 5 4 6 10 5 10 30 Appendix C Crest Audio FXA Series Power Amplifiers Models FXA601, FXA901, FXA1201, FXA2401, FXA3601, FXA4801 Appendix D Rear Panel Symbols - Legend Input Connection Section 1 3- FXA 2+ XLR Connector Polarity Indicator TRS Connector Polarity Indicator Ø 40x 20x dBu XLR Pin + + + + B Crest Audio FXA Series Power Amplifiers Models FXA601, FXA901, FXA1201, FXA2401, FXA3601, FXA4801 + A AB A AB AB AB GAIN Mode Selection Switch - Bridged Mono Position Mode Selection Switch - Parallel Position Mode Selection Switch - Stereo Position Chassis Ground Lift Switch - Ground Lifted Position Chassis Ground Lift Switch - Grounded Position Gain Select Switch (FXA4801) 2 3 XLR pin hot (+) select switch (FXA4801) Output Connection Section A B A B A 5-Way Binding Post Output Connection - Channel A Stereo/Parallel A B 5-Way Binding Post Output Connection - Bridged Mono 5-Way Binding Post Output Connection - Channel B Stereo/Parallel Appendix D FXA Appendix E FXA4801 Power Amplifier - Special Functions The FXA4801 rear panel features external switches for the following: XLR Pin+ Switch: This switch configures XLR input connection polarity. Either pin 2 or pin 3 may be selected as the "hot" (+) pin. Amplifiers are shipped pin 2 "hot" (+) from the factory. Gain Switch: This switch permits the amplifier to be configured for the standard input sensitivity (. 775V for rated power @ 8), or for optional voltage gains of X40 or X20. [. . . ]