User manual ADCOM GFA-555SE

[. . . ] GFA-555se OWNER'S MANUAL High-Current Power Amplifier Congratulations on your purchase of the Adcom GFA-555se You have made a wise choice that will reward you with exceptionally accurate musical sound reproduction for years to come. To realize the full potential of your new amplifier, please read these operating and installation instructions thoroughly before attempting to make any connections to it. The GFA-555se is not only designed to reproduce the highest quality sound but also to deliver the greatest possible value. It is our engineers' passion for perfection that has enabled our components to be judged the equivalent of others costing two, three, or even five times as much. [. . . ] Although the GFA-555se can generate a substantially greater amount of power in the bridged mono mode than when it is in its normal stereo mode, it requires the use of loudspeakers whose nominal impedance does not drop below 4 ohms. It is not recommended that the GFA-555se be used in the bridged mono mode into loudspeakers, or multiple loudspeaker loads, which drop in value substantially below 4 ohms. Otherwise, you may trigger the THERMAL PROTECTION or blow one of the DC RAIL FUSES. A little known fact is that when any amplifier is operated in the bridged mode, the load is "split" between the two amplifiers in the bridged configuration. Therefore, an 8-ohm loudspeaker will be seen by the amplifier as if it were a 4-ohm load; a 4-ohm loudspeaker load will be seen by the amplifier as a 2-ohm load. NOTES: a) If the connections described above are followed exactly, the GFA-555se will be polarity correct, that is, it will not invert "phase". Any positive-going signal at its input will appear as a positive-going signal at the loudspeaker. b) For use in professional installations, the GFA-555se may be mounted in a standard 19-inch rack using the optional RM-7 rack-mount adaptors available through ADCOM dealers. If the GFA-555se is to be mounted on a rack, along with other components which are interconnected to the GFA-555se, the amplifier's chassis must be insulated from the metal-rack rails to prevent ground loops, especially if the rack is grounded to "earth", and to avoid defeating the audio grounding scheme of the power amplifier (the audio-input grounds are isolated from and above the chassis ground). Please consult the instruction sheet packed with the optional rack-mount adaptors for more information. c) The DC RAIL FUSES provide protection for the output stages and power supply in the event of excessive current demands from the amplifier, either long-term or short-term. If the amplifier ceases to operate, either on one or both channels, particularly during high-level passages, or long-term high-volume playback, and the POWER LED glows while the THERMAL PROTECTION LED is out, the chances are that one or both of the DC RAIL FUSES on that channel, or both channels, are blown. In the event that the DC RAIL FUSES need to be replaced, refer servicing to qualified service personel. DO NOT USE ANY SUBSTITUTE FUSES WITH DIFFERENT RATINGS, TIME-CURRENT CURVES OR VALUES. Failure to observe this precaution may cause serious damage to the amplifier circuits, MAY CREATE A FIRE HAZARD, AND MAY VOID YOUR WARRANTY. 8 REAR PANEL (1 ) (2 ) (1 ) (2 ) (6 ) (3 ) (4 ) (5 ) FRONT PANEL model GFA-555se power high current power amplifier instantaneous distortion alert R L channel thermal protection (7 ) (8 ) (10) (9 ) (1) Inputs (unbalanced) (2) Inputs (balanced) (3) Output Binding Posts (4) AC Fuse (5) AC Power Cord 9 (6) Mode Switches (7) On/Off Switch (8) Power LED (9) Thermal Protection LED (10) Distortion Alert LEDs DESCRIPTION OF UNIT: REAR PANEL (1) Inputs (unbalanced) The audio inputs for the GFA-555se are through high-quality, gold-plated RCA jacks to minimize high-frequency losses, noise, etc. They will accept standard RCA-type plugs, one for each channel; Left and Right. To insure that the performance designed into the amp is preserved, you should use the highest quality audio cables possible. There are many cables which are color-coded and specifically designed for this application. (See CONNECTING THE GFA-555se for more information). low-impedance loudspeakers. In either case, BE SURE TO REPLACE THE AC Fuse ONLY WITH AN EXACT REPLACEMENT FUSE. The proper fuse values are: GFA-555se for 115 volt operation Fuse Rating BUSS® Littelfuse® 12 Amp 250 Volt . . . (3AB) 314012/250V GFA-555se for 230 volt operation Fuse Rating BUSS® Littelfuse® 6 Amp 250 Volt . . . . [. . . ] The chassis, top cover and rear panel are heavy-gauge steel that has been powder coated and baked to ensure a lasting finish. If the front panel, top or sides become dusty or fingerprinted, they can be cleaned with a soft lint-free cloth, slightly dampened with a very mild detergent solution or glass cleaner. Do not spray or pour liquids of any kind directly onto the GFA-555se. SERVICING ADCOM has a Technical Service Department to answer questions pertinent to the installation and operation of your unit. If your problem cannot be resolved through our combined efforts, we may refer you to an authorized repair agency, or authorize return of the unit to our warehouse. To aid us in directing you to a convenient service center, it would be helpful if you indicate which major city is accessible to your home. Please address mail inquires to: ADCOM Service 8541 East Anderson Drive, Suite 101 Scottsdale, Arizona 85255 USA Phone, Fax or e-mail inquires to: Voice: (480) 607-2277 Fax: (480) 348-9876 Monday through Friday 9:00 AM to 5:00 PM MST E-mail: service@asi-pro. com For Fax inquires, please include a return Fax number for the reply. [. . . ]