User manual ADCOM GFA-6000

[. . . ] · Custom toroidal power transformer provides better regulation and greater peak current capability. · Independent thermal-overload and distortion LEDs for all 5 channels. · High quality, gold-plated 5-way binding posts. · High quality, gold-plated RCA jacks. [. . . ] To turn the GFA-7700 off, press the push-button in and release and it will move to the "disengaged" position. Power LED (7) This LED will glow whenever the On/Off Switch (6) is turned on and the GFA-7700 is energized. The Power LED indicates that there is AC voltage being fed to the amplifier, but it does not signify that all the amplifier's circuits are in operation. If, for example, one of the Thermal Protection LED (9) glows, that amplifier channel will not produce sound even though the Power LED may still glow. When the GFA-7700 is turned off, the Power LED will take some time to fade out completely. It may take up to 30 seconds to fully extinguish. Additionally, the internal power transformer is provided with a thermostat which will interrupt power into the transformer if its temperature exceeds 125°C. This high temperature will seldom, if ever, be encountered unless the amplifier is subjected to abnormal conditions, such as operation into loads of less than 3 ohms at very high listening levels, etc. If the AC Fuse (4) has not failed, the Power LED is out, and the Thermal Protection LED (9) does not glow, this would indicate that the thermostat within the transformer has opened. Once the temperature within the transformer decreases to a normal level, the thermostat will reset itself automatically and normal operation will resume. If you are to avoid continually tripping the thermostat in the transformer, you must reduce the sound level demands, correct the load impedance of the loudspeakers, or both. 7 Distortion Alert LEDs (8) The Distortion Alert circuit is a unique ADCOM distortion detection system which reads all forms of nonlinear distortion such as THD, IM, slew-induced, "clipping, " etc. The Distortion Alert LEDs will light when distortion reaches approximately 1% regardless of impedance, voltage/current phase angle or the reactance of the loudspeakers which the amplifier is driving. They are as follows: RS -- Right Surround LS -- Left Surround RF -- Right Front C -- Center LF -- Left Front 10 Inputs (1) To preserve the correct effects, be certain to connect the RCA cables to the proper RCA-input connector. If the cables are color coded, then use this sequence for the connections: Blue. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Left Front Red . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Right Front Green. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Center White with Blue Stripe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Left Surround White with Red Stripe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Right Surround The recommended maximum RCA cable capacitance should be less than or equal to 30pF per foot when measured between the two conductors, and less than or equal to 50pF per foot when measured between one conductor and the shield. With the DB-25 computer-type Multichannel input connector (3), there is no need to worry about color coding or properly connecting the RCA plugs, as this is done in one connector with one cable. The DB25 can easily transfer all five channels from the output of the processor unit to the input of the GFA7700 amplifier. There can be no errors with the DB-25, it is shaped so that it can only be connected in the proper direction. Contact your dealer to locate a DB-25 signal cable. Outputs (2) NOTE: The GFA-7700 is "polarity correct". That is it does not invert phase from input to output. [. . . ] For fax inquires, please include a return fax or voice number for the reply. When calling or writing about your GFA-7700, be sure to note and refer to its serial number as well as the date of purchase and the dealer from whom it was purchased. In the event the unit must be returned to our factory for service, you will be instructed on the proper procedure when you call or write for a Return Authorization. For warranty coverage, a copy of the original proof of purchase is required. [. . . ]