Adcom GFA-555MS manual Adcom, Thermal Protection LED

Page 16

INSTANTANEOUS DISTORTION ALERT LEDs

 

 

 

 

The INSTANTANEOUS DISTORTION ALERT

circuit

is a uni

que

ADCOM

distortiondetectionsystemwhichreadsallformso

fnonlineardistortionsuchasTHD,1M,

slewinduced,"clipping",etc.TheINSTANTANEOUSDI

STORTIONALERTLEDswilllight

whendistortionreaches1%regardlessoftheimpeda

nceorthephaseangleofthecurrent

voltageandthereactanceoftheloudspeakerswhich

theamplifierisdriving.Sometimes,

whentheamplifierisinuse,theLEDsmayoccasion

allyflickerunderhighvolumelistening,

particularlyifyouaredrivinglowimpedances.Thi

sflickeringisnocauseforconcern.The

LEDsaresimplywarningyouthattheamplifierisa

pproachingitsmaximumpoweroutput

into the specific loudspeakers which you are using.

If, however, the INSTANTANEOUS

DISTORTIONALERTLEDsglowbrightlyorareonmost

ofthetimeduringplayback,you

are overdriving the amplifier and should lower the

volume control to reduce the

listeninglevel demands, or you may blow the DC RAI

L FUSES, cause the THERMAL

PROTECTIONtobeactivatedor,inextremecases,da

mageyourloudspeakers.

 

THERMAL PROTECTION LED

 

 

 

 

 

The GFA555ms is provided with a thermal protection

circuit which will shut down the

amplifierifthetemperatureofeitherheatsinksre

aches85°C.TheTHERMALPROTECTION

LEDwilllightwheneverthethermalprotectioncirc

uitoneitherchannel,orbothchannels,

has been triggered and the amplifier is inoperative

. The thermal protection circuitry will

typicallybetriggeredbyveryhighpowerdemandsi

ntoimpedancesmuchlowerthanthe

amplifieriscapableofdrivingatthoselevels.If

theoutputofeitherchanneloftheamplifier

ceases abruptly, and the THERMAL PROTECTION LED glo

ws, you will know that its

heatsinks temperaturehas become unacceptably high

and thecircuitryis protecting the

amplificationdevices.PleasenotethatthePOWERL

EDwillremainonandtheamplifierwill

stillbeenergized.

 

 

 

 

 

Oncethetemperatureoftheheatsinksdrops toasa

feoperatinglevel,theamplifier will

automaticallyreturntooperation.

 

 

 

 

 

If the amplifier ceases to operate and both the POW

ER LED and the THERMAL

PROTECTIONLEDare off,theconditionmayindicatethattheACLINEFUSE

 

hasblown.

PleaserefertothesectionACLINEFUSEeforinst

ructionsonreplacingthisfuse.

 

Image 16
Contents High Current Power Amplifier Introduction PrefacePage Important Notice Adcomprotectionplan U.S.AONLY UnpackingPage RIGHT/LEFT Input RIGHT/LEFT Stereeo Speaker OutputsSTEREO/BRIDGEDMONOINPUT/OUTPUT Page Page STEREO/BRIDGED Mono INPUT/OUTPUT DC Rail Fuses MAY TstereospeakeroutputsDC Rail Fuses Bussman LittelfuseAC Line Cord AC Line FuseVoid Your Warranty AC Line Fuses BussmanSOC CES612A Do not USE ANY Substitute Fuses With Different RatingsAC ON/OFF Switch Power LEDAdcom Thermal Protection LEDActivationofthethermalprotectioncircuitryint Indication Thattheamplifierhasbeenoverdriveno RthattheloadADCOMUSA/J&BDISTRIBUTION PHOENIX,AZ85078Page GFA-555ms Specifications Page General

GFA-555MS specifications

The Adcom GFA-555MS is a high-performance power amplifier that has established a reputation for its reliability and excellent sound quality. This amplifier, developed by Adcom, an American audio company known for producing high-quality audio components, is often sought after by audiophiles and professionals alike for its unique features and robust build.

One of the standout characteristics of the GFA-555MS is its impressive power output. With a continuous power rating of 200 watts per channel into 8 ohms, and even more when driving lower impedances, it provides ample power to drive a wide variety of speakers. This ensures that users can enjoy dynamic sound reproduction, whether they are listening to music at moderate volumes or cranking it up for a party.

The GFA-555MS is designed using a high-current, Class AB topology, which strikes a balance between efficiency and sound fidelity. This design allows for clean, detailed audio reproduction while minimizing distortion. The amplifier is renowned for its ability to handle complex musical passages and reproduce them faithfully, making it a favorite among music lovers who appreciate the nuances of their favorite recordings.

Another notable feature is its advanced thermal management system. The GFA-555MS is equipped with substantial heat sinks and a robust power supply that allows it to operate efficiently without overheating. This is particularly beneficial for sustained listening sessions or when driving demanding speaker loads.

In terms of connectivity, the GFA-555MS offers various input options, including RCA and XLR connections, making it versatile enough to integrate into a range of audio systems. This flexibility is complemented by its exceptional build quality, with a solid chassis that not only enhances durability but also minimizes vibrations that could interfere with sound quality.

The amplifier also includes additional features such as DC protection circuitry and a comprehensive output stage protection system. These safeguards help protect both the amplifier and the connected speakers from potential damage due to short circuits or overheating.

Overall, the Adcom GFA-555MS stands out in the realm of audio amplifiers. Its combination of power, sound quality, and advanced technologies make it a preferred choice for both casual listeners and serious audiophiles. Whether for home theater setups or music playback, the GFA-555MS delivers performance that is hard to match, making it a true classic in the audio world.