ElectroVoice-A30-pwr-维修说明书手册含电器原理图

34Tw74InstructionsELECIRO.VOICE.INCModel A30 AmplifierBUCHANAN MICHIGAN30-watt CirclotronHigh-Fidelity Line AmplifierGENERAL DESCRIPTION-The Electro-Voice Model A30 amplifier is a highquality 30-watt line amplifier with provision for supplying the power necessary tooperate associated remote control and preamplifer equipment.Convenientplug-in connections are provided for this purpose.The polished chrome andSpecifirblack baked enamel finish presents an attractive appearance and provides maxi.mum protection against corrosion.onsFEATURES-No output tube DC in transformer.The Model A30 employs thenew Wiggins CIRCLOTRON circuit.DC output current is removed fromthe output transformer through the use of a bridge circuit.All switching transients are eliminated through unity coupling of output tubes:class AB,operationis effected with the resultant improvements in power output.effciency and tubelife.The primary impedance of the output transformer is one quarter of thatfound in conventional amplifier output circuits.affording a vast increase in powerInstructionsoutput at extremes of the frequency spectrum.A damping factor control permits perfect coupling between the amplifier andloudspeaker system eliminating the usual loss of bass from overdamping orhangover due to underdamping.For the first rime,through the use of thiscontrol,optimum operation of any speaker system is assured.Fig.1-Model A30 AmplifierSPECIFICATIONSPower Output:30 watts rated,60 watts on peaksSee Fig.2 "Maximum Undistorted Powervs.Frequency"ELECTRO-VOICEFreqvency Response:0.25 db 20 to 70,000 cps at rated outputSee Fig.3 "Frequency Response"Harmonic DistorlionLess than 0.5%at rated outputModelIntermodulation Distortion:Less than 1%at rated outputSee Fig.4 "Power vs.Intermodulation Distortion"LineHum and Noise:90 db below rated outputSpeoker Oulput:4 ohms,8 ohms,16 ohms unbalanced:600-ohm bolancedAmplifierFeedback:Loop feedback:16 db negativeDrive plate:2 db ponitiveOutput circuit:17 db negotiveTotal31 db negativeFig.2-Maximum Undistorted Powervs.FrequencyDamping FactorAdjustable between 0.1 ond 15.See table forcritical damping factors of all E-V speakers.Input Impedance:250.000ohmSensitivity:1.25V RMS…Electto Voue patents pening