ISA1350 120V Model The amplifier shall contain all solid-state circuitry, using complementary silicon output devices. The amplifier shall operate from 50–60 Hz AC power and shall draw 1200 VA or less when driven with random program material at 1/8 of rated power into 4-ohm loads. The amplifier shall have a 320-C19 16A IEC mains connector and shall be equipped with a removable power cord having a standard NEMA AC plug. The amplifier shall have 2 15A circuit breakers on the rear panel, and shall operate safely from a 15A 120V AC outlet. The amplifier shall comply with FCC part 15 Class B requirements. The amplifier shall have internal heat sinks cooled by forced air, driven by a 24-volt DC fan whose speed shall vary in response to heat sink temperatures to minimize acoustic noise. The fan's speed shall be controlled by a drive voltage ranging from approximately 9 volts when cool to approximately 24 volts when at the upper ranges of its operating temperature. Air flow shall be from rear to front to avoid temperature rise inside equipment racks; rack mounting of multiple amplifiers shall be possible without clearance for ventilation. The amplifier shall be capable of continuous operation at 1/3 of rated power into 4-ohm loads, in ambient temperatures up to 104° F (40° C). The amplifier shall contain two independent amplifier channels powered by a conventional power supply with a toroidal transformer. Each channel’s output section shall operate in Class AB+B. All amplifier protection systems shall be synchronized and self-resetting upon removal of fault. Each channel shall have circuitry to protect against short circuits or mismatched loads. Each channel shall independently monitor heat sink temperature and shall trigger fan speed boost, and if necessary, signal muting to prevent excessive temperature rise. Both channels shall have synchronized on-off muting, acting for several seconds after turn-on, and within ¼ second after turn-off or loss of AC power. Each channel's output section shall be AC coupled to protect the load against DC faults. Each channel shall have an independent and defeatable clip limiter and a 12 dB per octave high-pass filter. The corner frequency of the filter shall be selectable between 30 Hz and 70 Hz. The front panel shall contain these features: an AC power switch; a green LED status indicator for power; independent LED channel output indicators for signal present or -30 dB (green), and clip (red). The gain controls shall be located on the rear panel and have 11 detents. They shall be labeled in dB of attenuation, from 0 to infinity. From 0 to 14 dB, the attenuation steps shall be 2 dB per detent. The labeled attenuation settings shall be 0, 4, 10, 18, 25, and ∞ dB. The output connectors for both channels shall be barrier strips located on the rear panel, with screw terminals and a safety shroud. The terminals shall be arranged to facilitate bridged mono connection. The inputs shall be located on the rear panel, and shall consist of a 3-pin detachable terminal block and a 3-pin XLR connector for each channel. The XLR input shall be wired with pin 2 high. Inputs shall be electronically balanced, with a minimum impedance of 20 kilohms balanced and 10 kilohms unbalanced, and a common mode rejection of at least 50 dB from 20 Hz to 20 kHz. A High Density 15-pin DataPort connector shall be provided for carrying both audio and amplifier operational status signals to and from a QSControl network. The DataPort shall also accommodate plug-in crossover filters and other such accessories. A set of DIP switches on the rear panel shall be provided for: setting bridged mono and parallel-input operation; selecting clip limiters; and selecting high-pass filters and setting their frequencies. Each channel shall be capable of meeting the following performance criteria with both channels driven: sine wave output power of 800 watts into 8 ohms, 20 Hz to 20 kHz at <0.03% THD; 1300 watts into 4 ohms, 20 Hz to 20 kHz at <0.03% THD; and 2000 watts into 2 ohms, 1 kHz at <1.0% THD. Frequency response (with filters not engaged) at 3 dB below rated power shall be 20 Hz to 20 kHz ±0.2 dB. The maximum voltage gain shall be 64.0x, equivalent to 36.0 dB, and the 8-Ohm input sensitivity shall be 1.24 Vrms (+4.1 dBu). The unweighted signal to noise ratio over the range of 20 Hz to 20 kHz shall exceed 100 dB, referenced to full output. IHF damping factor shall exceed 200 with an 8 Ohm load. The amplifier chassis shall occupy three rack spaces and have provisions for securing the rear corners. Depth from mounting surface to tips of rear supports shall be 15.9 in. (40.4 cm). The amplifier’s weight shall not exceed 68.0 lb. (30.8 kg). The amplifier shall be the QSC Audio Products ISA1350. 230V Model The amplifier shall contain all solid-state circuitry, using complementary silicon output devices. The amplifier shall operate from 50–60 Hz AC power and shall draw VA or less when driven with random program material at 1/8 of rated power into 4-ohm loads. The amplifier shall have a 320-C19 16A IEC mains connector and shall be equipped with a removable power cord having a standard Schuko (CEE 7/7) AC plug. The amplifier shall have 2 8A circuit breakers on the rear panel, and shall operate safely from a 230V AC outlet. The amplifier shall comply with FCC part 15 Class B requirements. The amplifier shall have internal heat sinks cooled by forced air, driven by a 24-volt DC fan whose speed shall vary in response to heat sink temperatures to minimize acoustic noise. The fan's speed shall be controlled by a drive voltage ranging from approximately 9 volts when cool to approximately 24 volts when at the upper ranges of its operating temperature. Air flow shall be from rear to front to avoid temperature rise inside equipment racks; rack mounting of multiple amplifiers shall be possible without clearance for ventilation. The amplifier shall be capable of continuous operation at 1/3 of rated power into 4-ohm loads, in ambient temperatures up to 104° F (40° C). The amplifier shall contain two independent amplifier channels powered by a conventional power supply with a toroidal transformer. Each channel’s output section shall operate in Class AB+B. All amplifier protection systems shall be synchronized and self-resetting upon removal of fault. Each channel shall have circuitry to protect against short circuits or mismatched loads. Each channel shall independently monitor heat sink temperature and shall trigger fan speed boost, and if necessary, signal muting to prevent excessive temperature rise. Both channels shall have synchronized on-off muting, acting for several seconds after turn-on, and within ¼ second after turn-off or loss of AC power. Each channel's output section shall be AC coupled to protect the load against DC faults. Each channel shall have an independent and defeatable clip limiter and a 12 dB per octave high-pass filter. The corner frequency of the filter shall be selectable between 30 Hz and 70 Hz. The front panel shall contain these features: an AC power switch; a green LED status indicator for power; independent LED channel output indicators for signal present or -30 dB (green), and clip (red). The gain controls shall be located on the rear panel and have 11 detents. They shall be labeled in dB of attenuation, from 0 to infinity. From 0 to 14 dB, the attenuation steps shall be 2 dB per detent. The labeled attenuation settings shall be 0, 4, 10, 18, 25, and ∞ dB. The output connectors for both channels shall be barrier strips located on the rear panel, with screw terminals and a safety shroud. The terminals shall be arranged to facilitate bridged mono connection. The inputs shall be located on the rear panel, and shall consist of a 3-pin detachable terminal block and a 3-pin XLR connector for each channel. The XLR input shall be wired with pin 2 high. Inputs shall be electronically balanced, with a minimum impedance of 20 kilohms balanced and 10 kilohms unbalanced, and a common mode rejection of at least 50 dB from 20 Hz to 20 kHz. A High Density 15-pin DataPort connector shall be provided for carrying both audio and amplifier operational status signals to and from a QSControl network. The DataPort shall also accommodate plug-in crossover filters and other such accessories. A set of DIP switches on the rear panel shall be provided for: setting bridged mono and parallel-input operation; selecting clip limiters; and selecting high-pass filters and setting their frequencies. Each channel shall be capable of meeting the following performance criteria with both channels driven: sine wave output power of 800 watts into 8 ohms, 20 Hz to 20 kHz at <0.03% THD; 1300 watts into 4 ohms, 20 Hz to 20 kHz at <0.03% THD; and 2000 watts into 2 ohms, 1 kHz at <1.0% THD. Frequency response (with filters not engaged) at 3 dB below rated power shall be 20 Hz to 20 kHz ±0.2 dB. The maximum voltage gain shall be 64.0x, equivalent to 36.0 dB, and the 8-Ohm input sensitivity shall be 1.24 Vrms (+4.1 dBu). The unweighted signal to noise ratio over the range of 20 Hz to 20 kHz shall exceed 100 dB, referenced to full output. IHF damping factor shall exceed 200 with an 8 Ohm load. The amplifier chassis shall occupy three rack spaces and have provisions for securing the rear corners. Depth from mounting surface to tips of rear supports shall be 15.9 in. (40.4 cm). The amplifier’s weight shall not exceed 68.0 lb. (30.8 kg). The amplifier shall be the QSC Audio Products ISA1350.