User manual ADCOM GFA-7605

[. . . ] OWNER'S MANUAL GFA-7605 & GFA-7607 Multichannel High-Current Power Amplifiers WELCOME Dear fellow ADCOM product owner, Welcome to the ADCOM family!For more than twenty years, ADCOM products have delivered excellent performance and value for customers around the world. Our products are designed by our experienced and demanding engineering team, built to the highest standards in our factory, and sold and serviced through dealers, custom installers, and other retailers whose primary goal is your complete satisfaction. We know you are anxious to hear your new amplifier in action, but please take a few minutes to read this owner's manual before connecting the amplifier to your system. [. . . ] It should be noted that many loudspeaker systems which are nominally rated at 4 ohms drop in impedance, in some parts of their frequency range, to as low as 2 ohms (and sometimes less). You will not experience difficulties even with these very low impedance loads unless you demand excessively high volumes levels from your system. It is not recommended that you run additional sets of speakers to the GFA-7605/7607. (If you choose to add remote speakers in another room, it is strongly suggested that a switching system to disconnect the non-home-theater speakers be incorporated when the surround sound, home theater mode is in operation). A device such as the ADCOM GFS-3 or GFS-6 Speaker Selector is strongly recommended. A Speaker Selector enables you to maintain good sonic integrity while giving you the flexibility to add speakers throughout your house. It is suggested that for all the channels follow this chart for speaker lengths and wire gauges. If longer runs are needed, it is best to consult with your ADCOM Dealer to maximize the performance of your system with your exact conditions. up to 24 feet AWGI6 up to 36 feet AWGI4 up to 58 feet AWGI2 7 GFA-7607 REAR PANEL (1) (3) (4) (2) (5) GFA-7607 FRONT PANEL LF distortion alert > thermal protection > C RF RS RB LB LS G F A 7607 (6) (7) (8) (9) (1) Input Jacks (2) Output Binding Posts (3) I2V DC Trigger (4) AC Fuse (5) AC Power Cord 8 (6) On/Off Switch (7) Power LED (8) Thermal Protection LEDs (9) Distortion Alert LEDs DESCRIPTION OF UNIT: REAR PANEL (4) AC Fuse (1) Inputs The audio inputs for the GFA-7605 and GFA-7607 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 of the channels. To insure that the performance designed into the amplifier 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. Your ADCOM dealer can help select the best cable for your needs. (See CONNECTING THE GFA-7605/7607 for more information). The AC Fuse protects the electronic circuits of the GFA7605/7607. This fuse, normally, will fail only if there is an overload within the GFA-7605/7607. It may, however, fail if the amplifier attempts to deliver very high power into very 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-7605 for 120 volt operation -- Fuse Rating: 13 Amp GFA-7605 for 230 volt operation -- Fuse Rating: 6. 5 Amp GFA-7607 for 120 volt operation -- Fuse Rating: 15 Amp GFA-7607 for 230 volt operation -- Fuse Rating: 8 Amp Before attempting to replace a failed fuse, be certain to unplug the AC Power Cord from the AC wall outlet to prevent possible electrical shock. Replace the AC Fuse only with one identical in type and rating as printed on the rear panel. DO NOT USE ANY SUBSTITUTE FUSES WITH DIFFERENT RATINGS OR VALUES. 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 (7) does not glow, it may be an indication that the AC fuse has blown. If you are using the 12V DC Triggering feature it may be possible that there is a problem with that connection. To determine if the problem is caused by a malfunction in the 12V DC system, remove the small plug inserted into the I2V DC Triggering jack. [. . . ] 0. 030% 0. 026% 0. 060% 0. 060% Frequency Response @ 1 Watt into 8 Ohms 10Hz to 20kHz. 1. 5Hz to 65kHz Dynamic Headroom Into 4 Ohms. 2. 00 dB Signal to Noise Ratio, "A" Weighted 125 watts into 8 ohms. 498 Rise Time 5kHz, 120V peak-to-peak square wave, 20% to 80%. [. . . ]