User manual ADCOM GFS-3

[. . . ] Our engineering team consistently strives to develop and design products that will exceed your expectations. Our goal at Adcom is to let more consumers hear high-end quality sound without paying high-end prices. All Adcom components are the result of a long-standing dedication to innovation, quality, simplicity, and value. Adcom: We have the power -- and now, so do you! AVERTISSEMENT DANGER D'ÉLECTROCUTION NE PAS OUVRIR WARNING: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE COVER (OR BACK); NO USER-SERVICEABLE PARTS INSIDE;, REFER SERVICING TO QUALIFIED SERVICE PERSONNEL. [. . . ] When in the bridged mono mode, input to the amplifier is made only through the LEFT input jack. The connection to the RIGHT input jack should be removed since the right-channel input portion of the amplifier is inoperative. Only a single loudspeaker is to be connected to the GFA-555se when in the bridged mono mode. Please note that connections made to the loudspeaker from the GFA-555se, when used in the bridged mono mode, are different from those made when the amplifier is used in the stereo mode. The LEFT RED output binding-post terminal (labeled BRIDGED MONO OUTPUT "+") should be connected to the loudspeaker input terminal color-coded RED (or labeled POSITIVE, "+", POS, 8 OHMS or 4 OHMS). The RIGHT RED output binding post terminal on the amplifier (labeled BRIDGED MONO OUTPUT "-") should be connected to the BLACK loudspeaker terminal (or labeled NEG, "-", C, COM, COMMON, G, or GROUND). Please note that if you want to insure correct stereo phasing with optimal bass response, you must observe these connections precisely. 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. Failure to observe this precaution may cause serious damage to the amplifier circuits, may create a hazard fire, and may void the warranty. If the Power LED (8) does not glow, it may be an indication that the AC fuse has blown. If you are not sure, or the amplifier displays other symptoms, please consult the RESOLVING PROBLEMS section on page 12. (2) Inputs (balanced) The audio inputs for the GFA-555se are through high-quality, Balanced XLR jacks to minimize high-frequency losses, noise, etc. They will accept standard XLR-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 specifically designed for this application. Your ADCOM dealer can help select the best cable for your needs. (See CONNECTING THE GFA-555se for more information). Fuse replacement To remove the fuse-holder cap, you will need a #2 standard Phillips screwdriver. Place the screwdriver in the recessed "crosshead" in the cap. Turn the cap counter-clockwise, until the cap releases out towards you. Grasp the cap with your fingers and pull it completely out. [. . . ] UNDER NO CIRCUMSTANCES SHOULD YOUR UNIT BE SHIPPED TO OUR FACTORY WITHOUT PRIOR AUTHORIZATION, OR PACKED IN OTHER THAN ITS ORIGINAL CARTON AND FILLERS. If the original shipping carton and its fillers have been lost, discarded, or damaged, a duplicate carton may be obtained from our Service Department for a nominal charge. Always ship PREPAID VIA UNITED PARCEL SERVICE (UPS) OR OTHER APPROVED CARRIER. DO NOT SHIP VIA PARCEL POST, since the packing was not designed to withstand rough Parcel Post handling. FREIGHT COLLECT SHIPMENTS WILL NOT BE ACCEPTED UNDER ANY CIRCUMSTANCES. 13 GFA-555se SPECIFICATIONS Power Rating (To FTC Requirements) 200 Watts continuous average power into 8 ohms at any frequency between 20Hz and 20kHz with both channels driven at less than 0. . 04% THD. [. . . ]