Adcom GFA-565 User Manual Download Page 7

the preamplifier to the RCA jack on the GFA-565 labeled LEFT INPUT and the right output of 

the preamplifier section to the RCA jack labeled RIGHT INPUT. 

 

RIGHT/LEFT STEREEO SPEAKER OUTPUTS

 

The  GFA-565's  connections  to  the  loudspeakers  are  made  through  high-grade  5-way, 

gold-plated  brass  binding-post  terminals  located  on  the  rear  panel.  These  terminals  will 

accommodate  either  bare  wire,  tinned  wire,  terminal  pins,  spade  lugs,  or  "banana  plugs", 

both  single  and  dual.  The  output  terminals  are  color-coded  RED  and  BLACK  to  indicate 

polarity.  To  insure  correct  stereo  phasing,  you  must  connect  the  RED  output  terminal 

(labeled "+") to the loudspeaker input terminal color-coded RED (or labeled POSITIVE, "+", 

POS,8OHMS or 4 OHMS). The BLACK binding post terminal on the amplifier (labeled "-") 

should  be  connected  to  the  BLACK  loudspeaker  terminal  (or  labeled  NEG,  "-",  C,  COM, 

COMMON, G, or GROUND).   

 

NOTE

 

The  GFA-565  is  polarity  correct;  that  is,  it  does  not  invert  "phase".  Any  positive-going 

signal at its inputs will appear as a positive-going signal at its outputs. 

 

The RIGHT STEREO OUTPUT should  be connected to the right-channel loudspeaker, as 

you  face  the  pair  of  loudspeakers,  and  the  LEFT  STEREO  OUTPUT  to  the  left-channel 

loudspeaker.   

 

Be  certain,  when  the  GFA-565  is  used  in  Its  stereophonic  mode,  the 

STEREO/BRIDGED  MONO  INPUT  switch  is  in  the  STEREO  position.

  Otherwise,  the 

amplifier will not operate in the stereo mode. You will amplify only the 

left

 channel through 

both  outputs  of  the  amplifier.  For  further  clarification,  please  refer  to  the  section 

STEREO/BRIDGED MONO INPUT/OUTPUT. 

 

In  order  to  insure  that  connections  to  the  loudspeakers  are  correct,  you  must  be  able  to 

identify each wire conductor of the loudspeaker cables at  both ends of the cables. This is 

relatively  easy  to  do  since  most  loudspeaker  cables  consist  of  two  parallel,  stranded 

conductors  in a flexible  insulation,  with a  coding  system for  wire  identification.  Sometimes 

there is a colored "tracer" wrapped around one of the conductors; some cords have one of 

the  conductors  colored  silver  and  the  other  copper;  some  have  a  "ridge"  molded  on  the 

insulation  on  one  of  the  conductors,  while  others  are  marked  with  a  "+"  and/or  "_".  Your 

ADCOM  dealer  also  sells  special  loudspeaker  interconnecting  cables  and  these  are  most 

often labeled with respect to polarity. 

 

Summary of Contents for GFA-565

Page 1: ...HIGH CURRENT POWER AMPLIFIER GFA 565 The contents of this manual are subject to change Please check our website www adcom com or www adcom usa com for the most current version Copyright 2011 Adcom LLC...

Page 2: ...can drive a very broad range of loudspeakers including those with very low impedances at sustained high power levels even when the impedances are highly reactive Great care was taken to insure that di...

Page 3: ...her efficiency was insured by using a toroidal design Additionally thermal and dynamic tracking of the bias for the triple Darlington driver and output stages is provided to insure that the amplifier...

Page 4: ...outer carton If any number is altered or missing you should notify us immediately in order to insure that you have received a genuine ADCOM product which has not been opened mishandled or tampered wi...

Page 5: ...t only will the heat generated by the amplifier affect the performance of equipment stacked on top of the GFA 565 but the free flow of air through the ventilating slots provided in the chassis of the...

Page 6: ...lication Your ADCOM dealer can help select the best cable for your needs RIGHT LEFT INPUT Unbalanced The audio inputs to the GFA 565 are through two high quality gold plated brass RCA jacks using Tefl...

Page 7: ...OUTPUT should be connected to the right channel loudspeaker as you face the pair of loudspeakers and the LEFT STEREO OUTPUT to the left channel loudspeaker Be certain when the GFA 565 is used in Its...

Page 8: ...hich you should observe in order to insure maximum performance from your amplifier It is most important that you make certain the wiring you have selected has as Iowa capacitance as possible All ampli...

Page 9: ...wer levels with no difficulty It should be noted here that many loudspeaker systems which are rated nominally at 4 ohms drop in impedance in some parts of their frequency range to as low as 2 ohms and...

Page 10: ...inal of the loudspeaker to the negative terminal of the loudspeaker and vice versa Repeat the listening test with the mono signal to make sure you are correct in your initial evaluation If you can now...

Page 11: ...of the DC RAIL FUSES e Please refer to the section RIGHT LEFT STEREO SPEAKER OUTPUT for further clarification A little known fact is that when any amplifier is operated in the bridged mode the load i...

Page 12: ...d their time current blowing points have been carefully selected and thoroughly tested to deliver optimal performance while still accomplishing their protective functions Replace these fuses individua...

Page 13: ...ts Its plug should be inserted in a standard 120V 60Hz outlet with a minimum capacity of 15amperes and should have a dedicated branch circuit It is not recommended that you connect the GFA 565 into a...

Page 14: ...g on the amplifier POWER LED does not glow a failed electronic component or other internal malfunction must be suspected Make no further attempts at fuse replacement or operation of the amplifier Refe...

Page 15: ...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 you have blown one or more of the DC RAIL FU...

Page 16: ...l to reduce the listening level demands or you may blow the DC RAIL FUSES cause the THERMAL PROTECTION to be activated or in extreme cases damage your loudspeakers THERMAL PROTECTION LED The GFA 565 i...

Page 17: ...ility The chassis top cover and rear panel are of heavy gauge steel both painted and baked If the front panel top or sides should become dusty or fingerprinted they can be cleaned with a soft Iintless...

Page 18: ...of purchase and the ADCOM authorized dealer from whom it was purchased In the event the unit must be returned for service you will be instructed as to the proper procedure when you call or write UNDER...

Page 19: ...05 THD 700 watts continuous average power into 8 ohms at any frequency between 20Hz and 20kHz at less than 0 1 THD bridged IM Distortion SMPTE 1 watt to 250 watts into 8 ohms 0 009 1 watt to 350 watts...

Page 20: ...10Hz to 20kHz 0 0 25dB Power Bandwidth 3dB 5 Hz to 100kHz Dynamic Headroom into 4 Ohms 2 5dB Signal to Noise Ratio A Weighted 250 watts into 8 ohms 110dB Gain 27 0dB Input Impedance 100 000 ohms Inpu...

Page 21: ...om logo are registered trademarks of Adcom LLC No part of this manual may be reproduced or electronically transmitted without the express written consent of Adcom LLC Adcom LLC shale not be liable for...

Page 22: ......

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