OWNER’S MANUAL GFA-7805 & GFA-7807 Multi-channel 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.
TABLE OF CONTENTS WELCOME . . . . . . . . ................................ 2 SAFETY INFORMATION ........................... 4 DESCRIPTION OF UNIT GFA-7805 FEATURES .............................. 5 GFA-7807 FEATURES .............................. 5 WARRANTY INFORMATION ......................... 5 INSTALLATION & HOOKUP UNPACKING THE GFA-7805/7807 .................. 6 INSTALLING THE GFA-7805/7807 .................. 6 OPERATION FRONT AND REAR PANEL DIAGRAMS ................ 7 DESCRIPTION OF UNIT: REAR PANEL .
N OCK THE FOLLOWING PRECAUTIONS AND SAFETY INSTRUCTIONS ARE REQUIREMENTS OF UL AND CSA SAFETY REGULATIONS Warning: To reduce the risk of fire or electric shock, do not expose this unit to rain or moisture.
GFA-7805 FEATURES • Precision-matched devices used throughout the signal path • 112,000 µF of power supply-filter capacitance to optimize transient response • Independent power supplies for each channel • Fewer gain stages improve signal reproduction accuracy • 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 • Balanced XLR inputs • High qualit
INTRODUCTION Congratulations on your decision to purchase the GFA-7805 or GFA-7807 multichannel power amplifier. The GFA-7805 and GFA-7807 have been designed to be high performance and musically accurate in a configuration specifically designed to integrate with any audio pre-amplifier. You have made a wise choice that will reward you for years to come with exceptionally accurate and musical sound reproduction.
(1) GFA-7807 REAR PANEL (2) GFA-7807 FRONT PANEL LF (3) C RF (5) RS RB LB LS distortion alert > G thermal protection > (6) (4) (7) (8) F A 7807 (9) (1) Input Jacks (4) AC Fuse (7) Power LED (2) Output Binding Posts (5) AC Power Cord (8) Thermal Protection LEDs (3) I2V DC Trigger (6) On/Off Switch (9) Distortion Alert LEDs 7
DESCRIPTION OF UNIT: REAR PANEL is an overload within the GFA-7805/7807. If your fuse fails please contact your dealer or ADCOM directly for a replacement or servicing. (1) Inputs The GFA-7805 and GFA 7807 have both balanced and unbalanced inputs for each channel. The unbalanced connection is made via the gold plated RCA jack and the balanced connection is made via the XLR input connection. Each channel also has a switch which selects the type of input for each channel.
(9) Distortion Alert LEDs automatically and normal operation will resume. If you are to avoid tripping the thermostat in the transformer continually, you must reduce the sound level demands, correct the load impedance of the loudspeakers, or both. The Distortion Alert circuit is a unique ADCOM distortion detection system which reads all forms of non-linear distortion such as THD, IM, slew-induced, “clipping,” etc.
WARNING WHENEVER CONNECTIONS TO OR FROM THE GFA-7805 & GFA-7807 ARE BEING MADE, BE CERTAIN THAT THE AC ON/OFF SWITCH OF THE AMPLIFIER IS IN THE OFF POSITION, THE AC CORD OF THE AMPLIFIER IS DISCONNECTED FROM THE AC WALL OUTLET AND THAT ALL ASSOCIATED COMPONENTS ARE OFF.
CONNECTING THE GFA-7805/7807 TO YOUR SPEAKERS When connecting the amplifier to the loudspeaker, it is vital to maintain proper polarity (positive to positive, negative to negative). On the GFA-7805/7807, the positive terminal is color coded RED and labeled “+,” and the negative is color coded BLACK and labeled “-”. The positive terminal on the speaker will be color coded RED, or will be labeled “+,” “pos,” “positive,” “8 ohms” or “4 ohms.
RESOLVING PROBLEMS Use the chart below to solve common situations that don’t require professional attention. If the steps stated in POSSIBLE SOLUTION do not resolve your problem, then please contact your ADCOM Dealer or call the ADCOM Customer Service Department. Any problems not covered here should be brought to the attention of your ADCOM Dealer or ADCOM Customer Service Department. SYMPTOM POSSIBLE REASON POSSIBLE SOLUTION Power LED does not glow. No sound AC Power Cord(s) not plugged in.
CARING FOR YOUR GFA-7805/7807 Great care has been taken by ADCOM to ensure that your amplifier is as flawless in appearance as it is electronically. The front panel is a heavy-gauge, high-grade aluminum extrusion carefully finished and anodized for durability. The chassis, top cover and rear panel are heavy-gauge steel that has been powder coated and baked to ensure a lasting finish.
GFA-7805 SPECIFICATIONS Power Rating (To EIA/CEA-490-A Requirements) 300 Watts continuous average power per channel into 8 ohms at any frequency between 20Hz and 20kHz with all channels driven at less than 1.00% THD. 450 Watts continuous average power per channel into 4 ohms at any frequency between 20Hz and 20khz with all channels driven at less than 1.00% THD. THD + Noise at 300 watts into 8 Ohms (Typical) 20Hz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GFA-7807 SPECIFICATIONS Power Rating (To EIA/CEA-490-A Requirements) 300 Watts continuous average power per channel into 8 ohms at any frequency between 20Hz and 20kHz with all channels driven at less than 1.00% THD. 450 Watts continuous average power per channel into 4 ohms at any frequency between 20Hz and 20khz with all channels driven at less than 1.00% THD. THD + Noise at 300 watts into 8 Ohms (Typical) 20Hz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ADCOM A division of Klein Technology Group, LLC 8551 East Anderson Drive, Suite 105 Scottsdale, Arizona 85255 Voice: (480) 607-2277 Fax: (480) 348-9876 http://www.adcom.
