Adcom GFA-7300 User's Manual
Contents
1. outputs rear main fo LEFT Ce Right Front Speaker GFA 7400 ER t D ate Surround Right Listening Viewing position NOTE Product shown is for reference only The GFA 7400 and GFA 7300 differ in appearance but have the same basic configuration CONNECTING THE GFA 7400 7300 Remember that the Left and Right designations are as you are sitting down in your listening viewing area On the rear panel the inputs and outputs are grouped in 5 bracketed sets one for each channel They are as follows GFA 7300 GFA 7400 RR Right Rear seiniin Surround Right SR LR Left REA Surround Left SL FR Front Righi eserinepueonea Front Right FR CACGOnte eannan Center C FEF rONU CER Jiii Front Left FL Olnputs Be certain to connect the RCA cables to the proper RCA input connector If the cables are color coded then use this sequence for the connections BU C e wba acname eames FL Front Left 1 Eee me ae ore FR Front Right Green sO AE EERENS C Center White with Blue Stripe eee LR Left Rear Surround Left White with Red Stripe ow RR Right Rear Surround Right outputs NOTE The GFA 7400 7300 is polarity correct That is it does not invert phase from input to output Any positive signals at its inputs will appear as a positive signal at its outputs When connecting the amplifier to the loudspeaker it is vital to maintain proper polarity po2. GFA 7400 8 GFA 7300 High Current 5 Channel Power Amplifiers 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 electric shock do not expose this unit to rain or moisture CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN AVIS RISQUE DE CHOC ELECTRIQUE NE PAS OUVRIR The graphic symbol of a lightning flash with an arrow point within a trangle signifies that there is dangerous voltage within the unit and it poses a hazard to anyone removing the cover to gain 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
3. Power Bandwidth 30B iurien a E a a a aaaea 1 5Hz to 65kHz Dynamic Headroom Into 4 OTIS ecstatic eiiru E avec ean Ea dubs opt EANAN EARNE EE tian dees 2 5 dB Signal to Noise Ratio A Weighted 100 watts into 8 ohms 2 2 eee eee cece reece ana eateneneneenees gt 110dB Gil rana ass eck A T Salsas aad ude lates E E R 29dB Input Sensitivity for VY Us sahsscie cw zum casba chats nievatatscn N A did rues EE 0 1 volts FOE 1 OO WV AUG eaaa A uals aaia E danapaeacea ody eoareieaet 1 0 volts input Impedance ccccesccsesssesssnssscsessssseseresssseestesessserssevasenenasencsarssaseneesssensanssesscouevaresesantssessnatansvaatusacassoasersrenesereratens 50KQ Damping Factor 20Hz to 20kHz ssseeernenereseersssserurnunsnerresrerensvererannreeerererersresnrnrennsunanereerereerennsesvsntarerneererererererererere e gt 400 Rise Time 5kHz 80V peak to peak square wave 20 to 80 eeessenssrrrrererusrerernrssnsererensnsnesresnrenernrererse reetenenes 4 5uS Power Consumption Continuous All Channels Driven OVESTA ae EE E e deca E E AR eam A auenses cad aimadaanddens lacie 96VA Maimun aaa ia aaa AAEE E E EEO NNOD EA A 1440VA 00 watts nto 8 OPUS ainena EEES e E A AEE A a eG RAEE 1165VA Power Available in 230VAC on special order ssssesesrssssissasersseseseseensererreeeserernerirnnentninererseeressrnnnnanussnseeeres 115VAC 50 60Hz Chassis DimenslonS sssssssreresirissosorsrsissssusucssskikor
4. dimmer halogen or Make sure all appliances dimmers and itself fluorescent light is creating interference suspect lights are off A special note on hum When there is a low volume hum audible throughout your speakers even with the main volume turned all the way down you have a common phenomenon known as a ground loop A ground loop is basically a difference in ground voltages between two or more components which are connected electrically and which creates multiple current paths where there must only be one This difference in potentials creates a 60Hz low level sound approximately a low A that seems to hum hence the name It can be caused by adding new components to your system but that does not imply there is anything electrically wrong with any new component With the advent of audio video and home theater systems the problem has become commonplace Generally the cause is the Cable TV incoming signal line This new incoming line may add an additional ground at a different potential to the AC line ground of your other equipment refer to Note 7 and 2 on next page to troubleshoot a hum problem 14 Note 1 Cable TV systems can sometimes contribute to ground loop problems which cause hum To determine if your cable system is the contributing factor disconnect the Cable TV incoming signal line round 75 2 at the wall or the first component the cable is connected to i e the cable box o
5. 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 poo The unit should be installed so that its location or position does not interfere with ts proper ventilation For example t shouid not be situated on a bed sofa rug or similar surface that may block the venttlation openings or placed in a bullt in installation such as bookcase or cabinet that may impede the flow of air through its ventilation openings The untt 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 tts 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 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 ts 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 personne
6. of the internal components It is imperative that these vents are not obstructed in any way We recommend that you do not stack other components on top of the GFA 7400 7300 This is particularly important if your system includes low impedance loudspeakers which are difficult to drive or if you will consistently demand high volume levels from the amplifier and speaker system Not only will heat generated by the amplifier affect the performance of equipment stacked on top of the GFA 7400 7300 but the free flow of air through the ventilating slots in the amplifier may be partially obstructed If you observe these recommendations the GFA 7400 7300 will perform reliably in any reasonable environment You should also pay attention to such normal considerations as protection from excessive dust and moisture Occasional vacuuming of accumulated dust on the chassis panels and around the ventilating slots should be all that is required The optimal performance of your new GFA 7400 7300 will ultimately depend on the care with which you make the connections between the amplifier preamplifier surround sound decoder and the loudspeakers All input and output signal connections should be made only with high quality low loss low capacitance cables following the recommendations in the Inputs and Outputs section of CONNECTING THE GFA 7400 7300 Left Front Speaker aa 874 74 rae 4 TTT a 2 Surround Left a r jja Foa apa
7. output devices e Convenient 12 VDC power ON OFF triggering e Heavy gauge anodized aluminum front panel e Powder coated baked chassis and top cover for greater durability e Cooling vents for greater efficiency and cooler operation while driving low impedance loads e Made in the USA GFA 7300 FEATURES e Precision matched devices used throughout the signal path e 47 000 uF of power supply filter capacitance for greater reserve capacity e Independent power supplies for each channel e Fewer gain stages improve signal reproduction accuracy Custom toroidal power transformer provides better regulation and greater peak current capability e Independent thermal overload and distortion LEDs for all 5 channels e High quality gold plated binding posts e High quality gold plated RCA jacks e Large independent internal heatsinks for greater cooling capability of output devices e Heavy gauge anodized aluminum front panel e Powder coated baked chassis and top cover for greater durability e Cooling vents for greater efficiency and cooler operation while driving low impedance loads INSTALLATION amp HOOKUP UNPACKING THE GFA 7500 and GFA 7300 Before your new ADCOM amplifier left our factory it was carefully inspected for physical imperfections and tested for all electrical parameters as a routine part of ADCOM s systematic quality control This along with full operational and mechanical testing should ensure a p
8. please consult the RESOLVING PROBLEMS section on page 13 10 Fuse replacement GFA 7400 To remove the fuse holder cap you will need a standard flat blade screwdriver Place the screwdriver in the recessed slot in the cap Turn the cap s turn counter clockwise until the cap pops out towards you Grasp the cap with your fingers and pull it completely out The fuse is inserted in the back of the cap gently pull it free since the fuse has a ceramic body you cannot visually examine the fuse element it is therefore suggested that you replace it with an identical substitute or bring the fuse to your Adcom dealer so they may check its integrity To replace the fuse insert it in the back of the fuse holder cap Place the cap into the fuse holder Place the screwdriver in the recessed slot gently press in and turn 1 g turn clockwise Fuse replacement GFA 7300 To remove the fuse holder cap you will need a 2 Philips type screwdriver Place the screwdriver in the recessed slot in the cap Turn the cap counter clockwise until the cap pops out towards you Grasp the cap with your fingers and pull it completely out The fuse is inserted in the back of the cap gently pull it free Replace it with an identical substitute or bring the fuse to your Adcom dealer so they may check its integrity To replace the fuse insert it in the back of the fuse holder cap Place the cap into the fuse holder Place the screwdriver in the recessed slot gentl
9. 15 250V For 230 volt operation 8 Amp 250 Volt AGC 8 250V 3AG 312008 250V GFA 7300 Fuse Rating BUSS Littelfuse For 115 volt operation T8 Amp 250 Volt MDL 8A 250V ZAG 313008 250V For 230 volt operation T4 Amp 250 Volt MDL 4A 250V 3AG 313004 250V WARNING 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 FIRE HAZARD AND MAY VOID THE WARRANTY lf the Power LED does not glow it may be an indication that the AC fuse has blown If you are using the 12VDC Triggering feature GFA 7400 Only it may be possible that there is a problem with that connection To determine if the problem is caused by a malfunction in the 12VDC system remove the small plug inserted into the 12VDC Triggering jack Press the front panel power switch to turn off the amp and immediately re press the power switch If the problem is caused by the 12VDC triggering circuit the amp will turn on and the LED will glow DO NOT attempt repair of the 12VDC system If you are not sure or the amplifier displays other symptoms
10. 28 sco eres accicnca a 2b didinicetiy ater Gelee coches a ETI Sica lt 0 025 ORNS A E E A E ts piedistisds Sasa A psn al elu AAN TA A 0 0075 a A E E E E A E E A A A AT E NEET 0 007 OWE NG irisssisticite aatacaatt Sea paictoan seu evade ag ba gue ahindbisdta ives ab a a Sacaia wenden e oe kes Jee 0 015 ri Aa T A caer E ETE A O E E E EE AE dudes agtclae chest cuss ca ieiie 0 025 LINE AE T E A I E E EN E A EA A A AE A EE 0 015 AORTA ace EE E A T O E E A eerie tol ec stead ei Sth aE a Meee wate ye vere 0 010 COU dese terpenes ant ans fuchematetctaasidy ies ea a a cnet tae oo gad tls date Gratin 0022 DIRT tice it sae ase est A E N tone aa A eh Sed Key veal tes cth8 tint econ pen Saute lac Ah 0 035 Frequency Response 1 Watt into 8 ohms 10Hz to 2OKHZ l coece ee 0 0 25dB Power Bandwidth 3dB n socssssscvssassssassusesausasasscsevaususuussvaseee eueveseececeecee o ceeee cee 1 5Hz to 100kHz Dynamic Headroom into 4 ONMS 00 ccccssssessse e desseseeseeesece cece 1 9 dB Signal to Noise Ratio A Weighted 60 watts into 8 OHMS 0 00 ce cccccceccsees ccccescscee cceseseee eeeesece cece bese ek gt 115dB CANIN 2 5a E A A E E PEE AA E das N AEAEE Pes ahac dt cases Bac Shoe ds sas Alaina ecg sae 29dB Input Sensitivity ta LSM re A E E E A E EERE ey eae EE 01 volts NOPSGO WY MUS E E AE setae Pah aie hand ceed tg ne Ai a AE ETN 1 14 volts MENU MTD OAC irai aa a a aa a ceased Bilacxpba lights A a S0kQ Da
11. 7300 Whenever the GFA 7400 7300 is energized the Power LED will glow To turn the GFA 7400 7300 on press the push button It will remain in the engaged position while the unit is energized To turn the GFA 7400 7300 off press the push button in and release and it will move to the disengaged position Power LED This LED will glow whenever the On Off Switch is turned on and the GFA 7400 7300 is energized The Power LED indicates that there is AC voltage being fed to the amplifier but it does not signify that all the amplifier s circuits are in operation If for example one of the Thermal Protection LED glows that amplifier channel will not produce sound even though the Power LED may still glow When the GFA 7400 7300 is turned off the Power LED will take some time to fade out completely It may take up to 30 seconds to fully extinguish Additionally the internal power transformer is provided with a thermostat which will interrupt power into the transformer if its temperature exceeds 125 C This high temperature will seldom if ever be encountered unless the amplifier is Subjected to abnormal conditions such as operation into loads of less than 3 ohms at very high listening levels etc If the AC Fuse has not failed the Power LED is out and the Thermal Protection LED does not glow this would indicate that the thermostat within the transformer has opened Once the temperature within the transformer decrea
12. It must never be connected to the switched outlets on the rear panel of a pre amplifier Usually this would mean that when you turn on off your pre amplifier you would have to turn on off your power amplifier separately We have however provided the ability to control the OFF ON function of the GFA 7400 by a 12Volt DC output jack on the rear of certain ADCOM pre amplifiers and tuner pre amplifiers When using this feature the front panel Power Switch must be left in the in on position To connect you will need a monaural mini phone plug to monaural mini phone plug cable of appropriate length not included to reach from the rear panel of the amplifier to the rear panel of the pre amplifier Contact your dealer for information on using this feature with ADCOM and other brand pre amplifiers Although 12VDC is optimal the circuit will operate from approx 9 to 30VDC not to exceed 250mv Center conductor tip is positive AC Fuse The AC Fuse protects the electronic circuits of the GFA 7400 7300 This fuse normally will fail only if there is an overload within the GFA 7400 7300 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 7400 Fuse Rating BUSS Littelfuse For 115 volt operation 15 Amp 250 Volt ABC 15 250V 3AB 3140
13. S 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 CARING FOR YOUR GFA 7400 7300 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 If the front panel top or sides become dusty or fingerprinted they can be cleaned with a soft lint free cloth slightly dampened with a very mild detergent solution or glass cleaner DO NOT SPRAY OR POUR LIQUIDS OF ANY KIND ON THE GFA 7400 7300 DESCRIPTION OF UNIT REAR PANEL NOTE Product shown is GFA 7400 GFA 7300 is similar Inputs The audio inputs for the GFA 7400 7300 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 Front Left Center Right Front Left Rear and Right Rear To insure that the performance designed into the GFA 7500 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 ne
14. 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 CAN NOT BE ACCEPTED UNDER ANY CIRCUMSTANCES 16 GFA 7400 SPECIFICATIONS Power Rating To FTC Requirements 100 watts continuous average power into 8 ohms at any frequency between 20Hz to 20kHz with all channels driven at less than 0 075 THD 150 watts continuous average power into 4 ohms at any frequency between 20Hz to 20kHz with all channels driven at less than 0 075 THD IM Distortion SMPTE A WHEE o 100 watts noS Ohmero aan a a A A lt 0 075 twat to 150 watts nOA ONM aiiin orn EE E AAEE EE aR lt 0 075 IM Distortion CCIF Any Combination from 4kHz to 20kHz TOO WATS NIOS ONS arona a a ss versa zeaua ce nedededa Code eieeudacais badeue E a autres TTE lt 0 025 IBO wans MOA ONTIS eian a a a a eae etme a OA THD Noise at 100 watts into 8 ohms Typical TAZ acetic A EEE E IEEE E E E E E E E E E E E T A 0 012 KHZ enairar A N E EAA N a 0 012 OKH oinor E E A E r 0 02 DOKL airsan A A E A aE EE ANER ssa evs 0 025 AL a V sacs EEE Fai EEA EE NEA SE AIEE OE EA OAE E E E E 0 025 IRH na RE E E E E NS 0 025 TORR ionnan a E E AEE E E A 0 035 POM ir aE AEE EE E SEA EEA ues E AAAA AARE EI E E E EEE E IE A T 0 045 Frequency Response 1 Watt into 8 ohms 10Hz to 2OKHZ nenenenesesenssererneseesserssnrsrernnnranernnsernsereserererenere 0 0 25dB
15. a 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 10 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 N GROUND CLAMP _ SERVICE ENTRANCE GONDUCTORS STANDOFF INSULATORS b MAST n SERVICE ANTENNA ENTRANCE LEAD IN WIRE EQUIPMENT ANTENNA DISCHARGE UNIT c TO EXTERNAL ANTENNA TERMINALS OF RADIO RECEIVER POWER SERVICE GROUNDING ELECTRODE SYSTEM e g intenor metal water pipe GROUND WIRE a b GROUND CLAMPS 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 NOTE TO CATV SYSTEM INSTALLER This reminder s provided to call the CATV system installer s attention to Article 820 22 of the National Electrical Code that provides guidelines for proper grounding an
16. asonably low If you wish to prevent recurrent activation of the thermal protection circuitry you must reduce the volume level demands or correct the load impedance condition which may be causing activation of this circuitry Distortion Alert LEDs 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 The Distortion Alert LEDs will light when distortion reaches approximately 1 regardless of impedance voltage current phase angle or the reactance of the loudspeakers which the amplifier is driving sometimes when the amplifier is in use the LEDs may occasionally flicker during high volume listening particularly if you are driving low impedances This flickering is no cause for concern The LEDs are simply warning you that the amplifier is approaching its maximum power output into the particular loudspeakers you are using If however the Distortion Alert LEDs glow brightly or are illuminated most of the time during playback you are overdriving the amplifier and should turn down your volume control to reduce the listening level otherwise it may cause the Thermal Protection to be activated or in extreme cases damage your loudspeakers TROUBLESHOOTING 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 prob
17. cal sound reproduction To realize the full potential of your new amplifier and before making any connections to it please read these operating and installation instructions thoroughly 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 2 GFA 7400 FEATURES e Precision matched devices used throughout the signal path e 100 000 uF of power supply filter capacitance for greater reserve capacity e Independent power supplies for each channel e Fewer gain stages improve signal reproduction accuracy e Custom toroidal power transformer provides better regulation and greater peak current capability e Independent thermal overload and distortion LEDs for all 5 channels High quality gold plated 5 way binding posts e High quality gold plated RCA jacks e Large independent internal heatsinks for greater cooling capability of
18. d 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 TABLE OF CONTENTS SAFETY INFORMATION e 1 INTRODUCTION WARRANTY INFORMATION 00 cecceeseeeeeeeeeeeeeeeeeneneeeens 2 DESCRIPTION OF UNIT FEATURES GFA 7400 creiria iE 3 FEATURES GFA T300 sanhi Aa 3 INSTALLATION amp HOOKUP UNPACKING THE GFA 7400 7300 vristim 4 PLACING THE GFA 7400 7300 oo cccc ces ee eee eeeeeeeeeeeees 4 QUICK CONNECTION ccmironenanion dan a 5 CONNECTION DIAGRAM sicccuiennssecieanscciucars Waaieieietesetncsnonss 6 INPUTS AND OUTPUTS rusis E 7 CARING FOR YOUR GFA 7400 7300 cece cece cence ees 8 OPERATION INPUTS AND OUTPUTS rissani a 9 FUSES AND AC SUPPLY suis eitiosticnstanedseiqeinaniamesacs 10 11 LED DISPLAY S saaria a a NAN 12 13 TROUBLESHOOTING RESOLVING PROBLEMS ccececeesseeeeeeneeeeeereneeneees 14 15 SERVICE INFORMATION soscrits setaiecsitiecciosauds 16 SPECIFICA TONS sisecteer to tcanetatie ei comaemn saan snieacodantevenst 17 18 INTRODUCTION Congratulations on your decision to purchase the GFA 7400 or GFA 7300 5 channel power amplifier The GFA 7400 and GFA 7300 have been designed to be high performance and musically accurate in a configuration specifically designed to integrate with any home theater processor You have made a wise choice that will reward you for years to come with exceptionally accurate and musi
19. dsiesasioaosnnrir sendsitasedorisrdesdndresas 5 127mm x 17 432mm x 14 355 6mm Maximum Dimensions cccssscesccecesseecssssseesenneneeecesscevevevensuarsrsessenesececeeeenes 5 146mm x 17 432mm x 15 381mm Weight ccccscsssssccsesecssesssssenseesesesnsorevesassensuscoaseeenessnaesensesaerensesressssseeseasaasoasorssesosoraseraestosessesrsasenesanseanenseateats 42 b 19 1 kg Weight Packed ccccccccsesceesesesesesssesesesssssessvessesseseeceaeersansnceessesecsenesasnersavapsesuaveuseusevaesuenenessecatusesersnenseseeesaeaes 48 Ib 22 8 kg All specifications are subject to change or improvement without notice Dimensions and weights listed are approximate actual product may vary slightly 17 GFA 7300 SPECIFICATIONS Power Rating To FTC Requirements 60 watts continuous average power into 8 ohms at any frequency between 20Hz to 20kHz with all channels driven at less than 0 075 THD 90 watts continuous average power into 4 ohms at any frequency between 20Hz to 20kHz with all channels driven at less than 0 075 THD IM Distortion SMPTE 1 watt to 60 watts into 8 ORMS enere nn cessescsevesiese aecceecoseveseeccg cece lt 007 1 watt to 90 watts into 4 ORMS reenn en sesesusrasaesesesceceeceseeeeseec ce aok lt 0 07 IM Distortion CCIF Any Combination from 4kHz to 20kHz OU WANS IMO 8 OMNIS ise sin scat E EE E E E EEE ie dikes EE lt 0 025 PO WAUES Mto A ONS 2s 2
20. eds See CONNECTING THE GFA 7400 7400 for more information 2 Outputs The GFA 7400 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 GFA 7300 s connections to the loudspeakers are basically similar there are two terminals for each speaker which are colored RED for the positive output and BLACK for the negative output The high grade gold plated binding post terminals on the GFA 7300 are however different These connectors easily accept stripped bare wires or pins To use spade lugs it is necessary to remove the black molded plastic guide block that fits over the binding posts To remove take out the two screws at the top and bottom of guide block Store the guide block and screws for future use 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 See CONNECTING THE GFA 7400 7300 for more information 12VDC Triggering GFA 7400 Only The GFA 7400 and GFA 7300 are very high power amplifiers and as such must be directly connected to the wall outlet or an appropriate surge protector or AC line conditioner
21. g you to a convenient service center it would be helpful if you indicate which major city is accessible to your home Please address mail inquiries to Phone Fax or E mail inquiries to ADCOM Service Corporation Voice 732 390 1130 11 Elkins Road Fax 732 390 5657 East Brunswick NJ 08816 Monday through Friday 9 00AM to 5 00PM EST E mail Service adcom com New Location and Telephone Numbers as of Spring 1998 ADCOM Service Corporation Voice 732 683 2356 10 Timber Lane Fax 732 683 2358 Marlboro NJ 07746 USA UNDER NO CIRCUMSTANCES SHOULD YOUR UNIT BE SHIPPED TO OUR FACTORY WITHOUT PRIOR AUTHORIZATION OR PACKED IN OTHER THAN ITS ORIGINAL CARTON AND FILLERS For fax inquires please include a return fax or voice number for the reply When calling or writing about your GFA 7400 7300 be sure to note and refer to its serial number as well as the date of purchase and the dealer from whom it was purchased In the event the unit must be returned to our factory for service you will be instructed on the proper procedure when you call or write for a Return Authorization For warranty coverage a copy of the original proof of purchase is required If you have no original copy please contact your dealer to obtain a duplicate copy 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
22. l when The power cord or the plug has been damaged or Objects have fallen or liquid has been spilled into the unit or The unit has been exposed to rain or liquids of any kind or The unit does not appear to operate normally or exhibits a marked change In performance or The device has been dropped or the enclosure damaged m oomp DO NOT ATTEMPT SERVICING OF THIS UNIT YOURSELF REFER SERVICING TO QUALIFIED SERVICE PERSONNEL ATTENTION POUR PREVENIR LES CHOCS LECTRIQUES NE PAS UTILISER CETTE FICHE POLARISEE AVEC UN PROLONGATEUR UNE PRISE DE COURANT OU UNE AUTRE SORTIE DE COURANT SAUF SI LES LAMES PEUVENT ETRE INSEREES A FOND SANS EN LAISSER AU CUNE PARTIE A DECOUVERT 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 POWER LINES Any outdoor antenna must be located away from all 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 antenn
23. lem 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 AC Power Cord not plugged in Plug in AC Power Cord glow No sound AC Fuse failed Replace AC Fuse Transformer thermal protection engaged Wait until unit cools down it will reset 12VDC triggering malfunctioning Reset power switch manually Check GFA 7400 Only connection of 12VDC trigger at source Power LED glows Preamp or source unit is not on Make sure whole system is on but no sound Connections in rear of amp are loose Verify all connections on rear of amp One channel not INPUT or OUTPUT connector Verify both connections on that channel producing sound disconnected or loose Speaker disconnected Verify connection at speaker Internal protection engaged Bring to Dealer or Service Center Hum from all speakers Ground loop difference in ground voltages If Cable TV is present see Note 1 at any volume between components If Cable TV is not present see Note 2 Hum from all speakers Problem with source unit CD tape etc Try different source tuner tape etc hum goes up or or RCA cable connecting that source unit and or different RCA cable down with volume to the preamp Hum from the amplifier Some major appliance
24. mping Factor 20Hz to 20kHZ e e ee och ee gt 800 Rise Time SkHz 90V peak to peak square wave 20 to 80 ce suceeee ceesesece cece 2 7uS Power Consumption Continuous All Channels Driven Eei g as cies seus E EEA E E E SE E N A A E E A EE ATE 80VA Ma e icc decile aa ested 960VA BO WANS NO CONME oira a e a E a a aa eka ceuncetas lt a 840VA Power Available in 230VAC on special order cccccccccccccsecssecssee ccssessrace a ceauevauere arrena eanan a aa 115VAC 50 60Hz Chassis Dimensions l oie cceecceccccsssesesssesescccceececcurecsneeesenecees seevavese eee us 4 1 118mm x 17 432mm x 14 355 6mm Maximum Dimensions 00 00 cccccccceseseceseesssceceusceceesssstaceveuersnesevevsnssececsueeseesenns o 127mm x 17 432mm x 14 375mm WY OUI E E Severed E EE E E E AE EEA haan acevaceiuceeninw EAE ETE 35 Ib 15 9 kg aee a e e e R E D ates E AE E E E E E E EAA 40 Ib 18 2 kg All specifications are subject to change or improvement without notice Dimensions and weights listed are approximate actual product may vary slightly 18 11 Elkins Road East Brunswick NJ 08816 USA Tel 732 390 1130 Fax 732 390 5657 Web http www adcom com New Location and Telephone Numbers as of Spring 1998 ADCOM 10 Timber Lane Mariboro NJ 07746 USA Tel 732 683 2356 Fax 732 683 2358 98KFTDO1 PRINTED IN THE USA
25. r VCR If the hum is no longer present you must insert a 75Q Ground Loop Isolator before reconnecting the line You should check with your Adcom Dealer to obtain one If the 75Q Ground Loop Isolator works only partially or not at all then please read Note 2 to complete the troubleshooting procedure Note 2 Make sure that the power amplifier is at least 6 from the Preamp and or Processor Usually putting another component between them is sufficient to minimize the hum If this does not reduce the hum turn the system off and disconnect all Inputs from the amplifier If the hum still persists then your Dealer or Service Center must examine the amplifier If the hum disappears try another set of RCA cables Connect one RCA cable at a time to see if one specific cable is responsible If any or all cables cause the hum to appear then the preamp or processor should be evaluated for proper operation by your Dealer or Authorized Service Center SERVICING ADCOM has a Technical Service Department to answer questions pertinent to the installation and operation of your unit In the event of difficulty please contact us for prompt advice Please have the following information readily at hand the unit s model and serial numbers and dealer from which it was bought If your problem cannot be resolved through our combined efforts we may refer you to an authorized repair agency or authorize return of the unit to our factory To aid us in directin
26. rable conditions Sound audio engineering practice suggests the use of at least AWG16 stranded copper cable Recommended capacitance of the speaker wire should not exceed SOpF per foot This insures high frequencies will not be rolled off It is suggested that for all the channels follow this chart for speaker lengths and wire gauges UD to 24 TOOL aau AWG16 UID 10 30 eBt AWG14 UD 10 08 fobl ocnaninani os AWG12 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 7 All loudspeakers having a nominal impedance down to 4 ohms can be connected to and driven by the GFA 7400 7300 The amplifier can drive these low impedance speakers at more than adequate power levels with no difficulty 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 7400 7300 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 GFS 4 or GF
27. roduct flawless in both appearance and performance After you have unpacked the GFA 7400 7300 inspect it for physical damage Save the shipping carton and all packing material as they are intended to reduce the possibility of transportation damage should the amplifier ever need to be shipped again In the unlikely event damage has occurred notify your dealer immediately and request the name of the carrier so a written claim to cover shipping damages can be initiated THE RIGHT TO A CLAIM AGAINST A PUBLIC CARRIER CAN BE FORFEITED IF THE CARRIER IS NOT NOTIFIED PROMPTLY IN WRITING AND IF THE SHIPPING CARTON AND PACKING MATERIALS ARE NOT AVAILABLE FOR INSPECTION BY THE CARRIER SAVE ALL PACKING MATERIALS UNTIL THE CLAIM HAS BEEN SETTLED PLACING THE GFA 7400 7300 i During normal home operation the internal heatsinks of the GFA 7400 7300 may become warm However there are instances during high level playback into low impedances when the heatsinks will become much warmer than usual To ensure the amplifier s long term trouble free operation it is necessary to provide adequate ventilation for the heatsinks Therefore the GFA 7400 7300 should be kept away from external sources of heat such as radiators and hot air ducts The GFA 7400 7300 should never be placed with other heat producing components in a cabinet or enclosure lacking free air flow The top and bottom panel of the amplifiers chassis have been provided with vents to allow the necessary cooling
28. ses to a normal level the thermostat will reset itself 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 Thermal Protection LEDs The GFA 7400 7300 are provided with a thermal protection circuit which will shut down the individual amplifiers if its heatsink temperature reaches 85 C The Thermal Protection LEDs will light whenever the thermal protection circuit in its respective channel has been triggered and the amplifier is inoperative The thermal protection circuitry will typically be triggered by very high power demands into impedances much lower than the amplifier is capable of driving at those levels If any amplifier channel s output through the loudspeaker s ceases abruptly and its Thermal Protection LED glows you will know that its heatsink temperature has become unacceptably high and the circuitry is protecting the amplification devices Please note that the Power LED will remain on and the amplifier will still be energized Once the temperature of the heatsink s drops to a safe operating level that amplifier will automatically resume operation Activation of the Thermal Protection circuitry in any of the amplifiers in the GFA 7400 7300 is an indication that the amplifier has been overdriven or that the load the loudspeakers are presenting to the amplifier is unre
29. sitive to positive negative to negative On the GFA 7400 7300 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 The negative terminal on the speaker will be color coded BLACK or will be labeled neg negative C Common G or ground It is recommended that your speaker cables be terminated with U type spade connectors These will give the most contact area insuring long term reliability The spade connector should have a maximum width of 0 57 inches and oe ee r an opening width of no less than 0 25 er eee see diagram on right lees To properly connect the speaker cable to the binding posts turn the insulated head of the binding post clockwise until the wire or connector is firmly secured Finger pressure is sufficient and vou should not use pliers or other tools which could damage or over tighten the binding post assembly The binding posts have been designed in such a way that finger pressure is all that is required to cause a pinching action among the different metal surfaces to ensure proper connection It is very important to use the correct size of wire in order to avoid unnecessary loss of amplifier power in the cable reduction of amplifier damping factor and other undesi
30. y press in and turn clockwise until fully inserted being careful not to over tighten AC Power Cord The AC cord provides power to operate all the GFA 7400 and 7300 s circuits Its plug can be connected to a standard wall outlet provided the outlet supplies a voltage compatible with the power requirements printed on the rear panel of the GFA 7400 7300 The GFA 7400 and 7300 s power cord is supplied with a polarized AC plug as required by UL CSA standards and the National Electrical Code To minimize the risk of electrical shock and to insure minimal hum from the system do not defeat the polarity insuring feature of the plug one wide blade and one narrow blade To prevent electrical shock do not use this polarized plug with an extension cord or AC outlet unless the blades can be fully inserted to prevent blade exposure FRONT PANEL L C R LR RR 1 Sy distortion alert gt C C a i C e GFA 7400 thermal protection gt O G o SC eg nar ae SS ee eee ear od SEE 6 re gt fi NOTE Product shown is the GFA 7400 The GFA 7300 is similar in appearance On Off Switch The On Off Switch controls power to the power transformer and circuits of the GFA 7400
Download Pdf Manuals
Related Search