User manual ART SLA-4

[. . . ] 8 Signal Indicator LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Clip Indicator LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Protect Indicator LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 REAR PANEL CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] 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)]. 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. 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. 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). If there is a fault condition at the speaker outputs (due to a severe load or short) the LED will light until the fault is removed. Channels One and Two share a Protect LED, as do channels Three and Four on the SLA-4. The protect lights will also light during power up and down, to indicate that the signal is muted. 9 REAR PANEL CONNECTIONS It is easy to interface the SLA-4 with a wide variety of equipment. Standard ¼" and Euroblock inputs and binding post outputs make patching simple. INPUTS The SLA-4 has two styles of input connections: ¼" TRS and Euroblock. Use these connections to connect the output signal from a mixer, preamplifier, crossover, or EQ to the amplifier. Balanced connections are recommended for cable runs longer than 20 feet. [. . . ] You may want to consult with your dealer for assistance in troubleshooting or testing your particular configuration. 2) If you believe the ART unit is at fault, go to www. artproaudio. com. You may contact Customer Service for more assistance, or directly request a Return Authorization for service in the "resources" area of the website. 3) If you are returning the unit for service, pack the unit in its original carton or a reasonable substitute. [. . . ]