Q-Tech Commercial Series QTA1120P/1240P Power Amplifiers User Manual QTA 1240P PUBLIC ADDRESS AMPLIFIER OUTPUT LEVEL Pwr -10 -8 -3 0 +3 +8 POWER
WARNING THIS APPLIANCE MUST BE EARTHED General Installation DO NOT run unbalanced high impedance microphone cables near mains, data, telephone or 70/100V line cables. DO NOT run 70/100V line cable near data, telephone or other low voltage cables. DO NOT exceed 90% of the amplifiers output power when using 70/100V line (speech only). DO NOT exceed 70% of the amplifiers output power when using 70/100V line (high level background music).
QTA-1120P/1240P User Manual Contents Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Front Panel Layout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Rear Panel Layout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Power Source . . . . . . . . . . . . . . . . . .
QTA-1120P/1240P User Manual Introduction Description Congratulations on your purchase of a new Q-Tech Commercial series amplifier. Quest Engineering Q-Tech Series amplifiers are engineered and built to a standard that will satisfy the most demanding environments of commercial installation audio. QTA series of Power Amplifiers cover models from 120W RMS to 480W RMS. This manual is to for 120W QTA-1120P and 240W QTA-1240P.
QTA-1120P/1240P User Manual Front Panel Layout 1 QTA 1120P 2 OUTPUT LEVEL PUBLIC ADDRESS AMPLIFIER Pwr -10 -8 -3 0 +3 +8 POWER 3 1 Power On Indicator LED 2 Level Indicator LED 3 Power Switch Rear Panel Layout 3 1 230V VOLTAGE SELECT AC 115/240V 50/60Hz BALANCED OUTPUT @ 10K ohms CAUTION BALANCED INPUT @ 10K ohms RISK OF ELECTRIC SHOCK DO NOT OPEN 24V DC COM 8Ω 70V 100V CAUTION: SENSITIVITY TO PREVENT ELECTRIC SHOCK DO NOT REMOVE COVER (OR BACK) NO USER SERVICEABLE PARTS T
QTA-1120P/1240P User Manual Power Source AC Power Source The supply transformer has been designed for AC 240V /115V (±10%) 50 /60 Hz. DC Power Source Battery Connection (24Vdc) When using external batteries, please ensure the amplifier is grounded via the screw terminal. (Electrical stability of the system will be improved by providing a good earth ground.) When connecting batteries, please ensure correct polarity. Main Connections Each input has XLR and Phone jack input.
QTA-1120P/1240P User Manual Please ensure the switch is on the Mono position when you are not connecting to another amplifier. When it is connected to another amplifier, put the switch on Parallel position to maintain maximum gain. Installation Practice Step 1. Take a piece of figure-8 cable, connect the stripe/coloured wire to the 100V terminal and the uncoloured wire to the COM on the amplifier terminal strip. Step 2.
QTA-1120P/1240P User Manual Trouble Shooting If the amplifier fails to work as required, please check the following: No Power, No Lights • Make sure amplifier power switch is on. • Make sure mains power switch is on at the wall. • Check the mains and DC fuse. • Replace with only the correct type and rating.
QTA-1120P/1240P User Manual Technical Notes Constant Voltage Distributed Speaker Systems Demystified In a typical paging and background music speaker installation, quantity loudspeakers are placed across a single amplifier in a parallel wiring configuration (see Fig 1.). Each ceiling speaker will contain a small transformer and you will notice that the connection block near the transformer will have a common terminal (C or earth), and a number of wattage terminals.
QTA-1120P/1240P User Manual For the benefit of those who want to calculate the power of the system with a formula. See below: Determining power by calculating total impedance The alternative to counting the speaker taping watts is to calculate the total impedance of the line, which will also indicate the wattage necessary to drive the system correctly. The computational formula is voltage squared divided by impedance: Power = Voltage2 / Impedance.
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