C22

1 STEREOPREAMPLIFIERC22 CONTENTS1122388899101111111616 GENERAL DESCRIPTIONTECHNICAL DESCRIPTIONM echanical SpecificationsElectrical SpecificationsFRONT PANEL INFORMATIONINSTALLATIONCONNECTIONSAC ConnectionsAC PowerInput ConnectionsOutput ConnectionsLoudspeaker Phasing ConnectionsGround ConnectionOPERATING INSTRUCTIONSGUARANTEE3-YEAR FACTORY SERVICE CONTRACTOWNER'S MANUALC 22C22 STEREO PREAMPLIFIERGENERAL DESCRIPTIONThe Mclntosh C22 Stereophonic Pream-plifier is a control center for any stereophonicsound system. To increase your enjoyment ofstereo, this control center does four jobs withprecise , the control center amplifies weakelectrical impulses. As the record rotates onthe turntable, undulations in the groovesmove the pickup stylus approximately onethousandth of an inch, in any direction, fromthe rest position.

2 From this slight mechanicalmovement, the pickup stylus generates aweak electrical impulse on the order of a fewthousandths of a volt. To amplify and pre-serve the information in such an electricalimpulse, the finest amplifier performance , every sound system is used in adifferent acoustical environment. The tonebalance of the music is affected by variationsin environment. Also, people listening to themusic have varying ideas of correct tone bal-ance. To compensate for these conditions, ahigh-quality tone control center is , all stereophonic and monophonicrecords, both domestic and foreign, arerecorded with specific frequency equaliza-tion. The control center must accurately com-pensate for this equalization introduced inthe recording , programs can originate from sev-eral sources such as tuners, records, tapemachines, microphones, etc.

3 A control centeris needed to select and switch these sourcesseparately or in of these jobs are performed with excel-lence by the C22 also uses the new, exclusiveMclntosh PANLOC method of PANLOC system gives you absolute easeof installation, operation, and is the first professional installationtechnique to be used on stereo the PANLOC system a metal shelf ismounted first, then the preamplifier slidesinto position on this shelf. Depressing thePANLOC buttons on the front panel locks thepreamplifier firmly into place for normaloperation. To unlock the preamplifier, de-press the front panel PANLOC buttons asecond time. The preamplifier can now slideforward to the ADJUST position. The pre-amplifier will lock in this position approxi-mately 3 inches from the mounting you can adjust the output level controls,low frequency trim controls, tape equaliza-tion controls, phase switch and pilot lampintensity switch.

4 These controls are mountedjust behind the C22 front panel. Depressingthe ADJUST position holding latches on thesides of the chassis allows the preamplifierto be taken out of the PANLOC shelf, or toslide back into position against the you have enjoyed the outstandingperformance of the C22, you will understandwhy Mclntosh products have earned theirreputation as "THE BEST." Your MclntoshC22 Stereophonic control preamplifier willgive you years of the finest possible perform-ance, and will become a highly valued part ofyour home music DESCRIPTIONThe C22 Stereophonic Preamplifier com-bines excellence in performance with ease ofoperation. The most often used controls havelarge diameter knobs. A new type of rockerswitch is used for the controls with simpleon-off functions. The C22 has an illuminatedfront panel with a light intensity switch toprovide convenient reading under low-levellighting conditions.

5 The Mode and InputSelector switch positions are also C22 circuit consists of 3 amplifiersections in duplicate for the left and rightstereo channels together with a commonpower supply. The first amplifier section is1the input preamplifier used to amplify andequalize signals from phonograph pickups,microphones or tape heads. Skillful circuitlayout, proper grounding, and adequateshielding reduce the hum so low it is virtuallyunmeasurable. Extreme care in manufactur-ing combined with low noise tubes, highspecific resistivity circuit boards, metal filmand wire wound resistors achieves new low inresidual second amplifier section follows themain volume control, making it impossible tooverload the high level input circuits or anyfollowing circuits. The same design tech-niques as used in the preamplifier sectionassure low noise and hum.

6 The BASS andTREBLE feedback-type tone controls operatein connection with this amplifier section. Thecontrols are switch-type with approximately4 db change per step. Exceedingly low distor-tion and precise control of frequency re-sponse contours are assured using panel tape jacks are provided forconvenient use of an external tape TAPE JACK switch connects the jacks foreither playback or recording through the third section is the cathode followeroutput. The sharp cutoff (18 db per octave)RUMBLE and HF (high frequency) filters areassociated with this section. OUTPUT LEVEL controls are located at the inputs of the cath-ode followers to allow simple balance of theentire amplifier-speaker system. The OUT-PUT LEVEL controls are located on top of theC22, behind the front panel. These controlsare conveniently accessible by releasing thePANLOC buttons and sliding the C22 out tothe adjust power supply deserves special men-tion.

7 The power transformer is constructedwith "core" type grain oriented laminationsand magnetic shielding for low external hum-fields. Long life rectifiers with full waverectification, filter condenser sectionalizingand careful grounding add to the hum-freelong life characteristics of the attention has been given to themechanical design. The PANLOC system isthe first professional installation techniqueto be used on stereo instruments. ThePANLOC system gives you absolute ease ofinstallation, operation and maintenance. TheC22 may be conveniently installed in furni-ture cabinets, custom-built installations, pro-fessional relay racks or an attractive finishedMclntosh SPECIFICATIONSSize:Front panel; 16 inches wide by 57/16 incheshigh; chassis (including PANLOC shelf) 15inches wide by 5 inches high by 13 inchesdeep, including connectors; clearance infront of mounting panel including knobs,1 :16 pounds net, 25 pounds in shipping :Anodized gold and black (front panel).

8 ELECTRICAL SPECIFICATIONSP ower Requirement:117 volts 50/60 cps AC, 34 Sensitivity and Impedance:Auxiliary, Tape, Tuner 1, and Tuner 2: , 250,000 1 and Phono 2: 2 millivolts, 47, : millivolts, 1 Head: 2 millivolts, 1 Compare: volts, 250,000 Response: db from 20 cps to 20,000 :Less than at 10 volts than .02% at 3 volts Noise:High Level Inputs: 85 db below rated Level Inputs: Less than microvolts atinput volts with rated Output:.25 volts with rated Plus Right Output:1 volt from generator impedance of 25, Amplification:Auxiliary, Tape, Tuner 1, and Tuner 2:To Main Output, 20 db (10 to 1).To Tape Output, 0 db (1 to 1).Phono 1 and Phono 2 (At 1 KC):To Main Output, 62 db (1250 to 1).To Tape Output, 42 db (125 to 1).Microphone:To Main Output, 60 db (1000 to 1).

9 To Tape Output, 40 db (100 to 1).Tape Head (At 500 cps):To Main Output, 62 db (1250 to 1).To Tape Output, 42 db (125 to 1). Outlets:1 unswitched (Red) for turntable or :6 each Jack Switch:2 position, connects panel jacks to allowsignals to be fed from or to the C22 torecord or playback using an externalportable tape Controls:Separate channel 11 position switch type, 20 db at 20 Controls:Separate channel 11 position switch type, 20 db at 20,000 Switch:RIAA or LP record Switch:Normal, or Tape Filter:50 cps Filter:5000 cycle Set-Up Controls:The following controls are located behind thefront panel on the top of the C22 controls are readily accessible bydepressing the PANLOC buttons to slidethe C22 forward from the mounting panel:Output Level Controls (L, L + R, and R).

10 Allows the balance of the entire system tobe conveniently Frequency Trim Controls (L and R):Allows frequencies below 100 cps to beboosted up to 6 db to compensate forunequal speaker Equalization Controls (L and R):Adjusts tape head input high Switch:2 position, normal (0 ) or reverse (180 ).Pilot Lamp Intensity Switch:2 position, bright or PANEL FACILITIESF igure 1. C22 Front SELECTORF igure 2. INPUT SELECTOR any one of eight program sourceswith this switch:1. AUX: any auxiliary service requiring flatamplification, such as a television set, isconnected to the C22 through the TAPE: any self-contained tape machine(tape machine having its own playbackpreamplifier) is connected to the C22through the TAPE TUNER 1: AM and FM or MPX FM outputsfrom a stereo tuner are connected to theC22 through the TUNER 1 TUNER 2: same as TUNER PHONO 1: connects the C22 for stereoand monophonic operation for PHONO 2: same as PHONO MIC: stereo microphones are connectedto the C22 through the MIC TAPE HD: a tape deck that does not con-tain its own playback preamplifier is con-nected to the C22 through the TAPE SELECTORUse the MODE SELECTOR to.