Midas XL401 Service Manual

1Operators & ServiceManualXL4KLARK TEKNIK GROUPKlark Teknik Building,Walter Nash Road, KidderminsterWorcestershireDY11 7HJEnglandTel: (01562)74151

10busses. If a switch is pressed for a short time it will latch on or off, but if it is held on for morethan 1 second the latching is disabled and whe

112. The ISOlate switches disconnect the vca sub group faders and mutes from automation screenrecall. Screen storage is still active.3. The vca MUTE

1212. The AUX I/P MUTE mutes every aux line return input on the GROUP modules.13. The INS LEFT and RIGHT switches connect the master left and right in

13XL422 Comms Pod.1. The METERS monitor the peak signal levels of the stereo AFL left and right solo busses or thePFL bus and local output level. The

1416. The TALK XLR socket accepts balanced 150 Ohm microphone signals from - 50dBu to -20dBu and uses an auto ranging gain system to bring the level t

15that are assigned to grand master vca B will be summed onto the solo busses when the vca solo isactive.Note i. When grand master vca B solo switch i

16controls to the matrix from post fader to pre fader.7. The MASTER LEFT controls give continuous adjustment of the master left signals that aresent t

17XL4 MODULE OPTIONS FUNCTIONAL DESCRIPTIONXL405 Stereo Input Pod.1. The MIC control gives continuous adjustment of left and right mic amp gains from

186. The LO MID control gives continuous adjustment of left and right boost and cut from +15dBto -15dB with a 0dB centre detent.7. The lo mid FREQ con

19XL414 Group Module (And Mic/Line Input).1. The AUX SEND controls give continuous adjustment of the mono aux bus output levels from+10dB to off.2. Th

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2018. The ST switches connect the post fader audio sub group signals to the stereo master bus viathe pan controls.19. The group PAN controls place the

21XL4 CIRCUIT DESCRIPTION1. Earthing System.The XL4 uses a multiple grounding system to control the interference effects between its internaldigital,

22- 18 volts at 20 amps referenced to 0VA+ 48 volts at 0.7 amps referenced to 0VA+15 volts at 10 amps referenced to 0VF- 15 volts at 10 amps reference

233. Mono Input Pod.The input pod has separate mic and line inputs, hi and lo pass filters, a direct output and a 20 ledmeter.The mic input signal pas

244. Mono Input Module.The input module houses the analogue insert, EQ, VCA, mute, pan and bus feed circuits alongwith logic circuits to control routi

25increase current drive capabilities of the buffers when required. Crosstalk and noise are kept to aminimum within the module and the console bus sys

26gain of the circuits by 55dB. It does this by effectively shorting out the negative current feedbackto greater or lesser extents. High frequency sta

27The insert return circuits are fed via T filters in the frame to differential amplifiers IC3 and IC5.Pre-sets VR2 and VR7 provides CMR adjustment an

28summed into all the bus send circuits and provides a clean earth for all the aux outputpotentiometers. VR5 adjusts the DC offset on the active earth

29clipping and it is matched by pre-set VR1 so as to give the maximum CMR when the signals arede-balanced by amplifier IC2. The differential gain of t

3DECLARATION OF CONFORMITYThe Directive Covered by this Declaration89/336/EEC Electromagnetic Compatibility Directive, amended by 92/31/EEC & 93/6

30and AC coupling is via C87 and C93.The aux send signal can be sent to the solo busses via CMOS switch IC12 which is controlled byNAND gate IC13. Sec

31low charge held on C155; once this capacitor has charged to a logic high the solo can be clearedby the solo clear bus via section C of IC26. If the

32C107. Further filtering is achieved by T filters in the console frame and AC coupling is via C86,C87, C97 C98, C108 and C109.The signal mutes are sw

33IC5. It is possible to link the talk and comms system via SW5; when the link is active the outputfrom amplifier IC3 is summed into amplifier IC5 via

34also applied to control the oscillation via resistor R128. This is shorted out by FET Q4 if theoscillation amplitude is too low but once the oscilla

35The comms module plays no part in the cancelling mode of operation but it is used to select theadditive mode via section A of invertor IC37 and sect

36IC32. Pre-sets VR10 and VR13 provides CMR adjustment and capacitors C77, C78, C81, C82,C96, C97, C98 and C99 provide additional high frequency filte

37The stereo aux signal can be sent to the solo busses via CMOS switch IC5 which is controlled byNAND gate IC8. Sections A and C of the NAND gate form

38for the bar graphs to run from whilst transistors Q3 and Q4 provide constant current for the bargraph leds. this is programmed by transistor Q5 whic

39XL4 Technical Specification.Input Impedance Mic 2K BalancedLine 20K BalancedInput Gain ( all faders at 0dB ) Mic Continuously variable from+ 15dB to

4ATTENTION!The following special limitations apply to the console and must be observed in order to maintainsafety and electromagnetic compatibility pe

40Line to Mix Noise( 48 channels routedat 0dB, pan centre ) - 75dBDistortion at 1kHz Mic to Mix ( + 60dBgain, 0dBu output ) < 0.03%Line to Mix ( 0d

41Colour Green Up to + 9dBu Normal signalColour Yellow + 12dBu to + 15dBu High signalColour Red Over + 18dBu Signal Too HighQuantity 77 ( Monitoring a

42Bass Gain Continuously variable+ 15 dB to - 15 dBCentre detent = 0dBBass Shelving Freq. Continuously variable3dB point from 20Hz to 400HzBass Bell F

43MIDAS XL4 SCHEMATIC DRAWINGSXL490-02 Power supply LED boardXL490-01 Power supply filter boardXL402-1 Input podXL402-2 Input podXL402-3 Input podXL40

44XL421-7 Master module - Main connectors & PSUXL431-1 Comms module - VCA control voltage & talk micXL431-2 Comms module - VCA control voltage

5CONTENTSMIDAS XL4 FUNCTIONAL DESCRIPTIONXL402 INPUT POD 6XL401 INPUT MODULE 6XL403 INPUT VCA FADER 8XL412 GROUP POD 9XL411 GROUP MOD

6XL4 FUNCTIONAL DESCRIPTIONXL402 Input Pod.1. The MIC control gives continuous adjustment of the mic amp gain from + 15dB to + 70dB2. The PAD switch g

76. The treble FREQ control gives continuous adjustment of the frequency range that the trebleequaliser acts on from 1K to 20K.7. The treble BELL swit

821. The mono aux PRE switches change the signal sent to the mono aux busses from post fader topre fader.22. The ST AUX controls (1 to 8) give continu

95. The VCA INPUT fader gives continuous adjustment of the input channel level from + 10dB tooff.XL412 Group Pod.1. The AUX switch changes the functio