Adcom GFA-7000 User Manual

/DCOM

details you can hear

G FA-7000

High Current THX®

5-Channel

Power Amplifier

LUCASFILM

THX

OWNER’S MANUAL

THE FOLLOWING PRECAUTIONS AND SAFETY INSTRUCTIONS

ARE REQUIREMENTS OF UL AND CSA SAFETY REGULATIONS

Warning: To reduce the risk of fire or eiectric shock, do not expose
this unit to rain or moisture.

CAUTION

A

RISK OF ELECTRIC SHOCK

DO NOT OPEN

'f

AVIS: RISQUE DE CHOC ELECTRIQUE-NE PAS OUVRIR

The graphic symbol of a lightning flash with an arrow
point within a triangle signifies that there is dangerous
voltage within the unit and it poses a hazard to anyone
removing the cover to gam access to the interior of the
unit Only qualified service personnel should make

any such attempt.

The graphic symbol of an exclamation point within an
equilateral triangle warns a user of the device that it is
necessary to refer to the instruction manual and its
warnings for proper operation of the unit

Do not place this unit on an unstable cart, stand, tripod,
bracket, or table The unit may fall, causing serious
injury to a child or adult, and serious damage to the
unit Use only with a cart, stand, tripod, bracket, or table
recommended by the manufacturer, or sold with the
unit Any mounting of the device should follow the man
ufacturer’s instructions, and should use a mounting ac
cessory recommended by the manufacturer

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, for example, near a bathtub, washbowl,
kitchen sink, laundry tub, in a wet basement, or near a swimming pool

The unit should be installed so that its location or position does not interfere

with Its proper ventilation For example, it should not be situated on a bed,

sofa, rug, or similar surface that may block the ventilation openings, or
placed in a built-in installation, such as bookcase or cabinet, that may
impede the flow of air through its ventilation openings

The unit should be situated away from heat sources such as radiators, heat
registers, stoves, or other devices (including amplifiers) that produce heat

The unit should be connected to a power-supply outlet only of the voltage
and frequency marked on its rear panel

The power-supply cord should be routed so that it is not likely to be walked
on or pinched, especially near the plug, convenience receptacles, or where
the cord exits from the unit

ATTENTION

POUR PRÉVENIR LES CHOCS ÉLECTRIQUES NE PAS UTILISER
CETTE FICHE POLARISÉE AVEC UN PROLONGATEUR, UNE PRISE
DE COURANT OU UNE AUTRE SORTIE DE COURANT, SAUF SI LES
LAMES PEUVENT ÊTRE INSÉRÉES À FOND SANS EN LAISSER AU
CUNE PARTIE À DÉCOUVERT

CAUTION

TO PREVENT ELECTRIC SHOCK DO NOT USE THIS POLARIZED PLUG
WITH AN EXTENSION CORD, RECEPTACLE OR OTHER OUTLET UN
LESS THE BLADES CAN BE FULLY INSERTED TO PREVENT BLADE
EXPOSURE

CAUTION

Any outdoor antenna must be located away from all power lines.

POWER LINES

OUTDOOR ANTENNA GROUNDING

If an outside antenna is connected to your tuner or tuner-preamplifier, be
sure the antenna system is grounded so as to provide some protection
against voltage surges and built-up static charges. Section 810 of the
National Electrical Code, ANSI/NFPA No. 70-1984, provides information with
respect to proper grounding of the mast and supporting structure, grounding
of the lead-in wire to an antenna discharge unit, size of grounding
conductors, location of antenna discharge unit, connection to grounding
electrodes, and requirements for the grounding electrode.

a. Use No.10 AWG (5.3 mm=^) copper. No.8 AWG (8 4 mm^) aluminum,
No.17 AWG (1 0 mm“) copper-clad steel or bronze wire, or larger, as a
ground wire.

b Secure antenna lead-in and ground wires to house with stand-off
insulators spaced from 4-6 feet (1.22-1.83 m) apart.

c Mount antenna discharge unit as close as possible to where lead-in
enters house

d. Use jumper wire not smaller than No.6 AWG (13.3 mm“) copper, or the
equivalent, when a separate antenna-grounding electrode is used. See NEC

Section 810-21 (j).

EXAMPLE OF ANTENNA GROUNDING AS PER NATIONAL ELECTRICAL CODE INSTRUCTIONS

CONTAINED IN ARTICLE 810 - RADIO AND TELEVISION EQUIPMENT

POWER LINES

STANDOFF
INSULATORS, b

ANTENNA
LEAD-IN WIRE

Clean unit only as recommended in its instruction manual

The power-supply cord of the unit should be unplugged from the wall outlet

when It IS to be unused for a long period of time

Care should be taken so that objects do not fall, and liquids are not spilled,
into the enclosure through any openings

This unit should be serviced by qualified service personnel when
A The power cord or the plug has been damaged, or
B Objects have fallen, or liquid has been spilled, into the unit, or
C The unit has been exposed to ram, or liquids of any kind, or
D The unit does not appear to operate normally, or exhibits a

marked change in performance, or

E The device has been dropped, or the enclosure damaged

DO NOT ATTEMPT SERVICING OF THIS UNIT YOURSELF.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.

TO EXTERNAL ANTENNA

POWER SERVICE GROUNDING
ELECTRODE SYSTEM

(e g interior metal water pipe)

BONDING JUMPER, d

OPTIONAL ANTENNA GROUNDING
ELECTRODE DRIVEN 8 FEET (2 44 M) INTO
THE EARTH IF REQUIRED BY LOCAL
CODES SEE NEC SECTION 810-21 (f)

TERMINALS OF RADIO RECEIVER

GROUND WIRE, a.b

GROUND CLAMPS

NOTE TO CATV SYSTEM INSTALLER

This reminder is provided to call the CATV system installer’s attention to
Article 820-22 of the National Electrical Code that provides guidelines for
proper grounding and, in particular, specifies that the cable ground shall be
connected to the grounding system of the building, as close to the point of
cable entry as practical

GFA-7000 FEATURES

Precision-matched devices used throughout the signal path.
120,000 pF 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 thermal-overload and distortion LEDs for all 5 channels.

High quality, gold-plated 5-way binding posts.

High quality, gold-plated RCA jacks.
Large independent, internal heatsinks for greater cooling capability of output

devices.

Heavy gauge, anodized aluminum front panel.
Powder-coated, baked chassis and top cover for greater durability.
Cooling vents for greater efficiency and cooler operation while driving low
impedance loads.
Home THX® standard DB-25 connector to simplify installation
Made in the USA

TABLE OF CONTENTS

INTRODUCTION

WHAT IS HOME THX®?........................................................2

WARRANTY INFORMATION.................................................2

DESCRIPTION OF UNIT

REAR PANEL.........................................................................3

FRONT PANEL

INSTALLATION & HOOKUP

UNPACKING THE GFA-7000

PLACING THE GFA-7000......................................................7

QUICK CONNECTION DIAGRAM

CONNECTING THE GFA-7000..............................................9

CARING FOR YOUR GFA-7000

TROUBLESHOOTING

RESOLVING PROBLEMS...................................................11

SERVICE INFORMATION

SPECIFICATIONS

......................................................................

................................................

.........................................

..........................................

...................................................

...............................................................

5

7
8

10

12
13

Thx . THX®, and Home THX® are registered trademarks of Lucasfilm Ltd

Dolby ProLogic® and Dolby AC-3® are registered trademarks of Dolby Laboratories Licensing Corp

INTRODUCTION

Congratulations on your decision to purchase the GFA-7000, Home THX® certified, 5­channel power amplifier. Not only is the GFA-7000 certified for Home THX® systems, but it
will also integrate with any other home theater system, such as Dolby ProLogic® or Dolby
AC-3®, You have made a wise choice that will reward you with exceptionally accurate and
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.

WHAT IS HOME THX® ?

Home THX® is the system developed by Lucasfilm Ltd. to maximize the accuracy of film
soundtracks in a home environment. It is important as soundtracks and their related special
effects become a greater and greater part of the whole film viewing and listening experience.

In order for a component to display the Home THX® system mark, it has to conform to the

strict series of standards that were investigated and defined during the 1980's by Tom Holman

of Lucasfilm Ltd. A home theater surround system utilizing Home THX® certified components
throughout, will give the most accurate re-creation of the original sound tracks put on the film in
the creative “dubbing stage” by its director, conductor and sound designer. Approved Home
THX® components insure all the necessary improvements to deliver the intended effects of a
film in home theater sound reproduction. The benefits are:

• Clearer dialog

• Precise front-stage sound localization

• Expanded depth of the sound field

• Extended and smooth frequency response

• Wider dynamic range

• Smoother sound transition among channels
The Adcom GFA-7000 amplifier is designed not only to meet these standards, but to

exceed them and deliver the most accurate reproduction of Home THX®-encoded films.

ADCOM PROTECTION PLAN (USA ONLY)

ADCOM offers the enclosed valuable Limited Warranty. Please read the details on the

Warranty Card carefully to understand the extent of the protection offered by the Warranty, its

reasonable limitations, and what you should do in order to obtain its benefits. Be sure to verify
that the serial number printed on the rear panel matches the serial number on the outer carton.

If any number is altered or missing, you should notify us immediately in order to ensure that you
have received a genuine ADCOM product which has not been opened, mishandled, or

tampered with in any way. Always retain your original sales receipt as a proof of purchase.

DESCRIPTION OF UNIT

O RR, LR, R, C, L Inputs

The audio inputs for the GFA-7000 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 five channels; Left (L), Center (C), Right (R), Left Rear (LR), and Right Rear (RR).
To insure that the performance designed into the GFA-7000 is preserved, you should use the

highest quality audio cables possible. There are many cables which are Home THX® certified,
color-coded and specifically designed for this application. Your Adcom dealer can help select

the best cable for your needs. (See CONNECTING THE GFA-7000 for more information).

O RR, LR, R, C, L Outputs

The GFA-7000’s connections to the loudspeakers are made through high-grade, 5-way,

gold-plated binding post terminals. There are two terminals for each speaker, which are colored
RED for the positive (+) output and BLACK for the negative (-) output.

The binding posts will accept a variety of connector types; the most secure and prevalent

of these is the “U”-type spade connectors (at least 0.25” wide and maximum width of 0.57”),.
The terminal will also accept bare wire (up to AWG10) and “banana” type plugs (single or dual).

Pin connectors are not recommended for use with Home THX® equipment. (See CONNECTING

THE GFA-7000 for more information).

O DB-25 Multichannel Audio Input Connector

Input connections may be made with the optional DB-25 computer-type connector, which
is a Home THX® certified option when your Home THX® controller is provided with a similar
output connector. Using this type of connecting cable would override the need to use the RCA­type inputs (O). This mode of connection retains the same high level of signal transfer,
simplifies the job significantly and insures automatic, correct connections to all channels.