User manual ART SLA-4

[. . . ] SLA-4 FOUR CHANNEL STUDIO LINEAR AMPLIFIER USER'S GUIDE 2 The ART SLA-4 FOUR CHANNEL STUDIO LINEAR AMPLIFIER IMPORTANT SAFETY INSTRUCTIONS - READ FIRST . . . . . . . . . . . . . . . . . . . . . . . 4 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7 AC Power Hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Units manufactured for use outside of North America have been modified to comply with the required electrical specifications. AUDIO INPUT CONNECTIONS Audio connections to the SLA-4 are balanced or unbalanced ¼" [Tip = Hot (+), Ring = Cold (-), Sleeve = (Ground)]. Euroblock connections: can be wired balance or unbalanced. See diagram on page 11 SPEAKER LOAD SAFETY PRECAUTIONS Warning: For optimum performance and reliability, do not operate the amplifier with a speaker load of less than 4 Ohms per channel, or any combination of speakers that together are less than 4 Ohms. Using one speaker per channel, it must be rated at 4 Ohms or greater. When using two speakers per channel, in parallel, they must each be rated at 8 Ohms, or greater. When in bridge mode, the speaker load should be 8 Ohms, or greater. 6 SECURITY COVER For commercial installations it may be desirable to set the gain controls on the power amp, and then make them inaccessible to non-qualified operators. This can be accomplished by using the Security Cover Plate that is included with the SLA-4. Simply set the channel level controls to the desired gain settings and press the knobs into the chassis until they lock into their recessed position. Then remove the two small phillips head screws, one on each side of the four channel level controls. Use these same screws to attach the security cover plate to the front panel, thereby covering the four channel level controls, making them tamperproof. See diagram below 7 CONTROLS & INDICATORS ­ FRONT PANEL POWER SWITCH The Power Switch is located on the front of the unit, directly in the center. During initial installation, make sure the level controls for each channel are set to a low volume level before applying power. CHANNEL LEVEL CONTROLS The dials for the four channel level controls are located to the left and right of the Power Switch. When set to zero (fully clockwise), the level is at maximum. The level is reduced as you turn the control counterclockwise. The level controls are detented and calibrated in dB. SIGNAL INDICATOR LED This LED indicates that a signal is present. The LED will glow when the amplifiers output signal is within approximately 30dB of full scale. CLIP INDICATOR LED This LED indicates that the power amp is near clipping. This LED comes on when the output signal from the amplifier begins to distort. If there is significant clipping, lower the input levels to reduce clipping, as well as the risk of damage to the speakers/monitors. 8 PROTECT INDICATOR LED The LED will glow when the channels associated with it go into protect mode. In protect mode, the output signal to the speakers will be muted (channel specific). [. . . ] A relay disconnects the outputs under any of these fault conditions and automatically returns to normal operation once the fault is removed. The amplifier is stable into loads as low as 2 ohms (stereo mode), and 4 ohms (bridged mode) when used in a fixed or permanent installation. However, for continuous operation of all channels at mid to high signal levels, the amplifier should be operated with a minimum load of 4 ohms per channel in stereo mode and 8 ohms per channel in bridged mode, otherwise the overload and thermal protection circuitry may cycle the amplifier on and off as it protects itself. 15 WARRANTY INFORMATION Limited Warranty Applied Research and Technology will provide warranty and service for this unit in accordance with the following warrants: Applied Research and Technology, (A R T) warrants to the original purchaser that this product and the components thereof will be free from defects in workmanship and materials for a period of three years from the date of purchase. Applied Research and Technology will, without charge, repair or replace, at its option, defective product or component parts upon prepaid delivery to the factory service department or authorized service center, accompanied by proof of purchase date in the form of a valid sales receipt. [. . . ]