CROWN-D-150AII-维修操作说明书手册-3-of-6-D150ASIIService操作说明书手册_3-of-6

CROWND-150A SERIES II POWER AMPLIFIERRev.0c.Remove the 2 ohm load and place a 1596.1.6 IOC Circuitmicrohenry inductive load on the output.The IOC indicator should illuminate when theObserve the output waveform.It shouldoutput signal is driven into clip.be similar to that in Illustration 6-3.6.1.7 Signal to Noisea.With the input level controls fully CCW,use a20Hz to 20kHz bandpass filter on the output ofthe amplifier to measure the signal to noiseratio.Insure that it's greater than 110dB belowthe rated output power.6.1.8 Quiescent AC PowerQuiescent power should be less than 30 wattswith a line voltage of 120VAC.20 watts istypical.6.1.9 Mono OperationUsing only channel one for an input signal,insert a 1kHz sine wave with the dual/monoswitch in the mono position.Observe thatchannel two is 180 degrees out of polarity fromchannel one.Channel one input level controlshould vary both channel one and two outputsignal.Illustration 6-3Protection Circuit6.2 Troubleshooting ChartMemory WaveformThe following chart will be helpful inidentifying symptoms and possible defects in6.1.5 Intermodulation Distortionthe operation of model D-150A.For morea.Using a 60Hz-7kHz signal summed in a 4:1detailed troubleshooting contact the Crownratio (S.M.P.T.E.method)on the input of theengineering.amplifier with an 8 ohm load on the output,insure that the following specs are withintolerance at a rated power output of 80 watts.OdB through-25dB less than .01%-30dBthrough-40dB less than.03%6-3