User manual IMG STAGE LINE STA-1800

[. . . ] All connections must only be carried out or changed with the unit switched off. It is essential to observe the following items: The unit is suitable for indoor use only. Protect it against dripping water and splash water, high air humidity, and heat (admissible ambient temperature range 0 ­ 40 °C). Do not place any vessels filled with liquid, e. [. . . ] Warning - This appliance must be earthed. If the unit is to be put out of operation definitively, take it to a local recycling plant for a disposal which is not harmful to the environment. This PA stereo has especially been designed for stage and disco applications. The amplifier is provided for rack installation (482 mm/19"), but it may also be used as a table top unit. In each case air has to move through all ventilation slots without obstruction so that a sufficient cooling is ensured. Additional space should remain above and below the amplifier to ensure a sufficient ventilation. To prevent the rack from becoming top-heavy, the amplifier has to be mounted in the lower part of the rack. The front plate alone is not sufficient as a secure fastening. The unit has additionally to be supported by side rails or a bottom plate. All connections must only be carried out with the unit switched off!Both jacks are provided for balanced signals; the pin configuration is shown in figures 4 and 5. The input signal should have line level. 2) The maximum output power is reached in 2-channel operation (stereo or parallel) when connecting 4 speakers. Speakers, however, the output power will slightly decrease in this case. In bridge operation the maximum output power will be reached with an 8 speaker. When using the SPEAKER jacks (14), the contact pairs 1+/1- or 2+/2- can be used, as in the unit the contact 1+ is connected to 2+, and the contact 1- to 2-. When connecting the speakers, pay attention to the same polarity of all speakers. For bridge operation connect the positive pole of the speaker to the positive terminal of the left output and the negative pole of the speaker to the positive terminal of the right output. 6 also shows possibilities of connection for several speakers to one output. In each case it is stated which power rating (PMIN) each speaker must have as a minimum with the corresponding impedance (Z). When interconnecting several speakers, it is especially important to pay attention to the correct connection of the positive and negative contacts and that the minimum total impedance is 4 for 2-channel operation and 8 for bridge operation. Prior to the first switching-on, set the controls (6 and 8) to the left stop to - . [. . . ] The volume adjustment is made with the left control (6) together for both outputs. If it is activated, the LEDs PROT (2 and 12) light up and the speakers are switched off: 1. For a few seconds after switching-on (switch-on delay) 2. If a DC voltage occurs at the output If a short circuit occurs at the speaker output, the CLIP LED (5, 9) of the corresponding channel lights up. [. . . ]