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Summary of Contents for OC-150A

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Page 2: ...i s eliminaees the need a separately engage the range itchand insurea the meter needle wcrn8tPle accidently damaged The redram schemtic pargial enclosed illustrates t h e wiring changes There are no...

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Page 4: ...orm as specified GROWN also warrants the components and workmanship of tl 8i sequipment to befree from defectsfara pesid af3 yearsfromdateaf purchase This warranty does not end to fuses andJarcom pane...

Page 5: ...sact as B b U meters 8 METERS Meters calibrakd i dB 1 2 can be used 0monitoroutput signalievels eithgr in VU 01 PEAK Meter scales are calibratedindB and volt CAUf Never adjustthe mechanicaladjustscrew...

Page 6: ...om Input 2 is depressed and to speaker seteclorswitch then to selected speaker syslen3 1 2 selectsthe amount sf Benuationdesired see page 6 for either headphone jack 1 2 Amp 2 Signa fed to t eters whe...

Page 7: ...rmal operation If single channel operation is desired then strap X must be installed Additionally a similarstrap could beaddedto all inputs andthespeakt3rcablescouldbe reduced to 3 conductor eables An...

Page 8: ...f the input linesto thervvaamplirfi em This hmk upapplmta CROWNamplaemon V u m u s t becertginof hawthe pounds ilrecannmtab famyoucannsctanyatkrarn Inthisconfigurntian MOTES FIG 1 4 Add ma conduetovju...

Page 9: ...eereasing the load impedance too far For example by depress ing two speaker selector switches and a headphone sat at the same time the resultant impdame would be 27 ohms if all three were 8 ohm sys te...

Page 10: ...FIG 1 5...

Page 11: ...rpositi6n then carefully increa the volume for a csmfo table listening level Hww switch ts headphones white wearing heset The MAX psitian of the attenuator switch patches hesignal straight thraugh ts...

Page 12: ...m his monitor switching does a a ect the prarngram to the speake but aged5 only whet the meters read With hemetering circuit of the OC 150A it is possible ta pedarm an objective evaluation of program...

Page 13: ...e 5 8 s r other larger CROWN rack cabinets Ta prepare for such an iustallation firgt remsvetheburswket screwsretainingtheandbars 1 Align the angle brackets to tha unit and reie wfi the socket screws R...

Page 14: ...han f8 5db over 20 minutes LEB aawd right speaker as damplifier grounds isalat d so that amplifiers with forwitfP k g isolated channel ground may be used safely Rear panel swikkes a ow 3levels of atte...

Page 15: ...he OC 150A is essentially a mechanical As such it should greatly enhance the output evice designed with simplicity and precision flexibility of your hi fi system...

Page 16: ...farm the readingbing an avemge If that wawefarm is a sine WVE the av8rage is zeqo sa the meter king en average reswnding meter reads zero We could try to use a dire AC reading again because sf mechsrn...

Page 17: ...msnt are by passed Here how it works The waveform is sampiedefectronieaftyusing a sen sing circuit which measuqeseven the fastest peaks T is measurement isstored aleetr nically and then sesrtto he met...

Page 18: ...tive pae of the immdancc This is es sentially wastc c powersinceif dmsnat produrn any acoustical r soit Resistance is found in such places a5 in the wir ofthe s a k r waice csit 2 Same af the po er is...

Page 19: ...power is produced UP FIG 2 3 It should be clear that t b ideal laad in terms of producing aceustiea9 enerw would be one which minimize the reactive camwnant high amplifier efficiency while optimizingt...

Page 20: ...ings an the QC 1SOA are chiefly usefut a a camparabive analysis tmf Ysu might try computing power lasing the oaminal rated impedance af the speaker system Ihshoanld be clear from the above discussion...

Page 21: ...SO FOG 2 5 FIG 2 6...

Page 22: ...tor circuifa The comparator main tains a negativeoutput a5 longas thetiming network charge is positive In the VU mode this charge is removed very quickly by discl rarging the netwsrrh tkmugh a resisBo...

Page 23: ...d be dot te in the foflowing steps FIG 2 7 1 Removethetop cover o f the OC l50A Lmatethe four wires Tram the transformer going to a ter minal strip Left hand rear Gamer terminal strip is mounted an re...

Page 24: ...icaf Rsgisfggllas 16K ohm 2 waQ 1 film 20K ahm 4watt 1 MF 10K ahm 4wag I film 41 2M ohm 54 waB 1 M f Za8Mohm wag 5 22K ohm 4wa 10 10ohm 3 4 waM 10 2M ohm 56 wa8 5 100K ohm waft 10 188Kohm 6438 5 2 2K...

Page 25: ...Pushbbafi n switch csXlar 25K audio t a p r pot ccw 1 74Mohm M wag 1 fifm 392 ohm watt 1 film 113ahm w w a B 1 Film 49 9 ohm M wag 1 frtm Lamp sseket 25A 6 3V la66 bukb Light bracket assy PC switch m...

Page 26: ...internal star lackwasher 2365 Used to mount hafd timeconf als CHASSIS ASSEMBLY OC 15QA chassis 4P3hslE d e switch 093steel eyelet HTA fuseholder MDL 1 88 fuse AGC 1J16AFuse 3 18 8 power card male Heyc...

Page 27: ...Maunb over screw from barrier strips C I Mountedan 8J6AJ terminal strips eP Usedto mount 3503 Used to moarat 3503 I 2 Usedt omount barrier strips I Usedto mount banker strips 1 Usedta mount banri r s...

Page 28: ...Early units R27 was 4 7K and R18 was 56M All capacitors in micro farads all resistors inohms unlessotherwise noted R28 is meter calibration Never attempt to adjust R23 the drift adjust unless a 4 digi...

Page 29: ...ntacts b Switch handle not moving eorreetly t h o u g hi t s 3 posit ion range 5 a Faulty semiconductar device i n meter circuitry Q3 Q4 sc a 6 a Faulty component i n hold circuitry Ql IC l D C49 1 3...

Page 30: ...ter to the output of IC 2 and ground a S e t meter switch to peak and turn hold timeM controls full clsckwise b Remove s i g n a l from the input c DVM reading should n o t vary 001 v over a 30 sec pe...

Page 31: ...o n is attsmpted Then t h e manuel L n s t r u t t o n aon page 19 are v e r y m i a l a d f n g Tha sntfrs gruup Prom 5N q3QI t o 3650 350 uwfte was wired according t o drawing A enclosed Please care...

Page 32: ...DRAWING B f 3L from SVGR Brans 811jCbE8 famw BL RED...

Page 33: ...eading should hold at 120 V f o r 10 15 seconds Switch range switch t o 14 V t u r n hold time controls ta f u l l CCW and feed in a 10 V o l t s i g n a l t o Amp 1 1 1 input Use t h e output from an...

Page 34: ...ear as en input o f f s e t 3 Step 3 i f 91 i s leaky the circuit will catch a peak but hold time will not Be adjustable 4 Step 4 5 if meters seem jumpy on low ranges check Q3 or 04 for noise These ar...

Page 35: ...y A 100 o h 114 watt rssistor CPN 2872 is added between C3 and the emitter o f QS Tha enclosad board layout and schamptic illustrate the modification 93 and or 9 4 failure syrapta tsare several Typica...

Page 36: ...Drill Hales Cut Trace Add 100 ohm ResiWor...

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