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.
TABLE OF CONTENTS LETTER FROM THE ADCOM TEAM. . . . . . . . . . . . . . . . . 2 SAFETY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 DESCRIPTION OF UNIT GFA-555se FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 WARRANTY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . 5 INSTALLATION & HOOKUP UNPACKING THE GFA-555se . . . . . . . . . . . . . . . . . . . . . . . . 6 INSTALLING THE GFA-555se . . . . . . . . . . . . . . . . . . . . . . . .
THE FOLLOWING PRECAUTIONS AND SAFETY INSTRUCTIONS ARE REQUIREMENTS OF ETL AND ETLC SAFETY REGULATIONS • • • • • • • • • • • • • Read all the safety and operating instructions before connecting or using this unit. Retain this notice and the owner’s manual for future reference. All warnings on the unit and in its operating instructions should be adhered to. All operating and use instructions should be followed. Do not use this unit near water.
GFA-555se FEATURES • Precision-matched devices used throughout the signal path. • 60,000 μF of power supply-filter capacitance for greater reserve capacity. • 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 distortion LED for each channel. • High quality, gold-plated 5-way binding posts. • High quality, gold-plated RCA jacks.
INTRODUCTION Congratulations on your decision to purchase the GFA-555se power amplifier. By use of updated components in the classic ADCOM GFA-555 design, we have reestablished our heritage of high performance and audiophile quality at the greatest possible value. You have made a wise choice that will reward you for years to come with exceptionally accurate and musical sound reproduction.
CONNECTING THE GFA-555se When connecting the amplifier to the loudspeaker, it is vital to maintain proper polarity (positive to positive, negative to negative). On the GFA-555se , 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”.
To set the amplifier in bridged mono operation, flip the STEREO/BRIDGED input switch into the BRIDGED position. 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.
REAR PANEL (1 ) (1 ) (2 ) (2 ) (6 ) (3 ) (4 ) (5 ) FRONT PANEL model GFA-555se power (7 ) high current power amplifier instantaneous distortion alert R L channel (8 ) (10) thermal protection (9 ) (1) Inputs (unbalanced) (6) Mode Switches (2) Inputs (balanced) (7) On/Off Switch (3) Output Binding Posts (8) Power LED (4) AC Fuse (9) Thermal Protection LED (5) AC Power Cord (10) Distortion Alert LEDs 9
DESCRIPTION OF UNIT: REAR PANEL low-impedance loudspeakers. In either case, BE SURE TO REPLACE THE AC Fuse ONLY WITH AN EXACT REPLACEMENT FUSE. The proper fuse values are: (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.
(6) Mode Switches For normal stereophonic mode of operation, the STEREO/BRIDGED input switch should be set to STEREO. Otherwise, the amplifier will operate in the bridged mono input mode by which you will amplify only the left channel through both outputs of the amplifier. The BALANCED/UNBALANCED selector switches should be set to accommodate the type of input connectors that you are using.
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. AC Power Cord(s) not plugged in.
CARING FOR YOUR GFA-555se 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-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. 300 Watts continuous average power into 4 ohms at any frequency between 20Hz and 20khz with both channels driven at less than 0.04% THD. * 600 Watts continuous average power into 8 ohms at any frequency between 20Hz and 20kHz at less than 0..09% THD, bridged.
Input Sensitivity 200 watts into 8 ohms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.75V rms 1 watt into 8 ohms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130mV rms Damping Factor 2OHz to 2OkHz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8541 East Anderson Drive, Suite 101 Scottsdale, Arizona 85255 Voice: 480.607.2277 Fax: 480.348.9876 www.adcom.com GFA-555se_manual_v1.
