User manual AUSTRALIAN MONITOR KA1200

[. . . ] KA800 & KA1200 Operation Manual Please read carefully. This operation manual contains important information regarding safety precautions, installation, performance, operation and maintenance of your KAKA-Series power amplifier. You should familiarize yourself with the contents of this manual before operating your amplifier. IMPORTANT! Safety Precautions and Labelling The rear panel of the unit has a number of markings and internationally recognized symbols related to the hazards and precautions that should be taken when operating MAINS connected equipment. The presence of a LIGHTNING FLASH with an arrowhead contained within the boundaries of an equilateral triangle is intended to alert the user that dangerous uninsulated voltages may exist within the unit's enclosure. These voltages may be of a sufficient magnitude as to constitute the risk of an electrical shock. [. . . ] Avoid powering equipment within a system from multiple power sources that may be separated by large distances. Check the continuity of all interconnecting leads to your amplifier, ensure that there are no open or short circuited conductors. Ensure that the power handling of your load (speakers) can adequately cope with the power output of the amplifier. Before operating yourKA800/KA1200 amplifier, ensure that: The attenuators are at the "OFF" position (fully anticlockwise). The GROUND LIFT Switch is not engaged (should be in the "out" position). The BRIDGE Switch is not engaged if you are not running the amp in bridged mode. Level Matching The normal operating position for the attenuator is the "0 dB" position (fully clockwise, no attenuation). Turning the attenuator back (anticlockwise) reduces the input sensitivity by the amount marked on the attenuator scale (dial). NOTE: If full power output is required you should operate your amplifier with the front panel attenuator above the -15dB position, otherwise clipping of the input circuitry and its resultant distortion will occur before full output power is achieved. Sensitivity Your amplifier is a linear device operating with a fixed input to output voltage gain (less attenuation). The maximum output voltage swing is determined by the applied mains voltage, load, load type and the duty cycle of the applied signal. The voltage gain factor of your amplifier is: 37 (31. 5 dB) for a KA800 45 (33. 0 dB) for a KA1200 The input sensitivity for your KA800/KA1200 amplifier when the attenuator is at the "0" dB attenuation position (fully clockwise) is nominally: +4. 0dB (1. 23 volts in) for rated power into a 8 ohm load. +3. 0dB (1. 10 volts in) for rated power into a 4 ohm load. Powering Up REMEMBER The amplifier should be the last piece of equipment that you turn on and the first piece of equipment that you turn off. We recommend turning the attenuators on your amplifier down when turning the unit on. When you power up your KA800/KA1200 your amplifier KA800/KA1200, goes through an establishment period before it will 14 Operation Each channel of your KA800/KA1200 amplifier has a nominal balanced input impedance of 30kOhms (@1kHz) and should not present a difficult load for any signal source. the equipment feeding the amplifier) should have an output impedance of 600 Ohms or lower to avoid unwanted high frequency loss in the cabling. difference between the amp earth and source equipment earth appears to the amplifier's input as a signal and is amplified as hum. Ensure your mains power for the audio system is "quiet" i. e. without equipment on it such as airconditioning, refrigeration or lighting which may generate noise in the earth circuit. Ensure all equipment within the system shares a common ground/ safety earth point. This will reduce the possibility of circulating earth currents as the equipment will be referenced to the same ground potential. Ensure that balanced signal leads going to the amplifier are connected to earth at one end only. Hum Problems Most equipment is designed for minimum hum when used under ideal conditions. When connected to other equipment, and to safety earth in an electrically noisy environment however, problems will often occur. The three "E"s of hum and hum related noise which can plague your audio system are: a) Electrostatic radiation, b) Electromagnetic radiation, and c) Earth loops Electrostatic radiation capacitively couples to system elements causing an interference voltage that mainly affects higher impedance paths, such as amplifier inputs. [. . . ] Onlycompetent or qualifiedpersons should attempt any service or maintenance of your amplifier. Fans Due to the openness of the air path through your KA800/KA1200 amplifier, very little dust should settle within the amplifier. The unit has been designed so that any dust and/or foreign particles that do settle within the amplifier will not unduly hinder the cooling of the unit. The mesh grille in front of the fans will act to limit the amount of dust and lint entering the unit. You will find in time that there will be a build up of dust and lint on the grille which may start to hinder the airflow through the unit. Over time, dust may build up on the leading edge of the fan blades and reduce their cooling efficiency. [. . . ]