M521A — Stereo Input Module

M521A STEREO INPUT MODULE BALANCE SELECT The Balance insertion switch SW4 controls the selection of balance control (R2-R5 ) into the left and right bus assignment outputs_ 2 ) MODE IND ICATOR

:. DSI illuminates anytime the mode selector switch is off the stereo select (s) position 3 ) A/B A/B source selector Sw1 selects the stereo source when released and the B stereo source when depressed _ PHASE Phase reversal switch SW2 reverses the phase of the right channel with respect to the left channel 5 ) PHASE REVERSAL IND [CATOR DS1 Mluminates when phase reversal switch SW2 is depressed . PGM/PEAK Indicator DS2 Mluminates green when the level of the audio signal at the prefade insertion point is at or above the nominal system operating Tevel . The indicator will switch to red (overload condition) when the signal level reaches level of approximately 22 dB above the nominal AUXIL IARY ON Switches SW1O, SW12, SW14 and SW16 assign the audio signal to the appropriate auxiliary mix bus . PRE/PosT Switches Sw9 SW11 , SW13 and SW15 select the associated Auxiliary to either the prefade or postfade take off point. 3-1

M521A STEREO INPUT MODULE Note: Specifications are based on voltage levels of 600 ohm system unless other- wise specified_ Input Sensitivity: -10 to +10 dBm (ref . 600 ohm source) Frequency Response +/-0.25 dB from 30 Hz to 20 kHz Noise: Greater than 75 to 80 dB signal to noise ratio for input sensitivities of -10 to +10 dBm. Harmonic Distortion: Less than 0 .25% from 30 Hz to 20 kHz at +24 dBm output levels or less _ Less than 0.1% at kHz at +24 dBm output: Source mpedance 600 ohms or less balanced _ Input mpedances 30 , 000 ohms or greater Output Impedances: Less than 100 ohms at insert and direct outputs Load [mpedances 600 ohms balanced (at insertion point) 5000 ohms balanced (at direct outputs) .

Output Levels dBm nominal, +26 dBm maximum. Channel Separation: 60 dB _ Phasing: Low number or numbered terminals of the input pair is in phase with the similar terminals of the output pair_ Power Requirements +/-25 volts dc, 100 mA nominal , 185 mA maximum. +12 volts dc, 50 mA _ Ambient Temperature: to 60 degrees Celsius_ Dimensions 1.60" wide 14.15" high 6.50" deep (41 mm 360 mm 165 mm) Weight: Ibs 0z (1.14 kg) net 1-1

M521A STEREO INPUT MODULE This unit contains the Iatching circui try for both the program channel switch and the solo switch. These latches may be controlled either locally by momentary pushbuttons SW17 and SW18 or remotely through the console control system. DS3 is the Channel On tally and DS4 is the Solo On tally_ Eight tally sense points are fed into the control system via this control Subassembly The SA14-077 is powered by +12 volts which appears at P2 pin Y, while the logic control common is at P2 pin of the module connector Power Supely_Decoupling The +/-25 volt supply voltage applied to P2 pins 21 and 19 is regulated down to +/-18 volts by an active decoupler consisting of Q8 through Q11 with their associated components. Q12 and Q13 are current Iimit sensors for the positive and negative voltage supply rails. The common return for the +/-25 volt supplies is at P2 pins 20 and X, while the main frame chassis connection is at P2 pin 22 _ . . . , ' ` . < -. > ^. ' - ` .. e : . ` '

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M521A STEREO INPUT MODULE PART DESCRIPT ION MFG MFG PART NUMBER C1 C2 c3 C4 C5 Capacitor 4.7 uF/10 10 PF Kemet Philips T390B475M01OAS ` 2222-638-10109 delete Capacitor 33 uF/1o Kemet T3900336M01OAS C6 C7 c8 C9 C10 4p7 4p7 Philips 2222-638-09478 delete Capacitor 10 uF/25 10 uF/25 Kemet T390C106M025AS C11 C12 C13 C14 C15 uF/10 0.1 uF/100 V 10 PF T390B475M01OAS 1C1OXZRIO4MOSOB 2222-638-10109 Sprague Philips delete C16 C17 C18 C19 C2o Capacitor 33 uF/10 4p7 4p7 Kemet Philips T3900336M01OAS 2222-638-09478 delete Capacitor 10 uF/25 ~Kemet 2 Philips T390C106M025AS C21 C22 C23 C24 C25 10 uF/25 4.7 uF/10 4p7 4p7 T390B475M01OAS 2222-638-09478 delete C26 C27 C28 C29 C30 Capacitor 4.7 uF/10 4.7 uF/10 4.7 uF/10 4.7 uF/10 4.7 uF/10 Kemet T390B475M01OAS : , :' C31 C32 C33 C34 C35 C36 C37 4 .7 uF/1o 4.7 uF/10 4.

7 V uF/10 4 . 7 uF/10 4.7 uF/10 uF/35 uF/35 : ` .. . T390B105M035AS 5-1

M521A STEREO INPUT MODULE PART DESCR IPT |ON MFG MFG PART NUMBER C38 Capacitor C39 :. _ C4o . . 10 uF/25 4p7 4p7 Kemet Philips T39OC106MO25AS 2222-638-09478 C41 C42 . ` | . C43 C44 C45 4p7 4p7 10 uF/25 10 uF/25 10 uF/25 Kemet T390C106M025AS CL6 C47 C48 C49 C5o C . C51 C52 C53 C54 C5s 10 uF/25 10 uF/25 V 22 uF/25 22 uF/25 22 uF/25 Philips 426ETF22 22 uF/25 0 uF/100 0 . uF/100 10 uF/25 10 uF/25 Sprague 1C1OXZRIO4MOSOB Kemet T390C106M0125AS C56 C57 C58 C59 C60 CR1 CR2 CR3 CR4 CRS uF/100 uF/1oo uF/100 uF/100 uF/100 V Sprague 1C1OXZRTO4MOSOB

0 delete Diode Fairchild IN4148 CR6 CR7 CR8 CR9 CR1O

1N4003 CRI1 CR12 Schottky CR13 :.`; ` 1N5711

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