Klark Teknik XL4 User manual

1
Operators & Service
Manual
XL4
KLARK TEKNIK GROUP
Klark Teknik Building,
Walter Nash Road, Kidderminster
WorcestershireDY11 7HJ
England
Tel: [phone] Fax: [phone]

2

3
DECLARATION OF CONFORMITY
The Directive Covered by this Declaration
89/336/EEC Electromagnetic Compatibility Directive, amended by 92/31/EEC & 93/68/EEC
Equipment Type Product Name
Audio Mixing Console XL4
The Basis on which Conformity is being Declared
The Products named above comply with the requirements of the above EU directives by meeting
the following standards:
EN 55013: 1990
EN 50082: 1992
Signed: ............................ Alex Cooper
Authority: Project Leader
Date: 28th November, 1995
Attention!
The attention of the specifier, purchaser, installer or user is drawn to special limitations of use
which must be observed when these products are taken into service to maintain compliance with
the above directives. Details of these special measures and limitations to use are available on
request and are also contained in product manuals.

4
ATTENTION!
The following special limitations apply to the console and must be observed in order to maintain
safety and electromagnetic compatibility performance:
POWER CONNECTION
The console should only be operated with the power supply connected to ground via its mains
supply connector.
CONTROL CONNECTIONS
The console should only be operated with high quality screened control cables. All connector
shells should be of metal construction so that they provide a screen when they are plugged into
the console. All DEE connector shells should be connected to the cable screen. All XLR and
DIN connectors should have pin 1 connected to the cable screen.
AUDIO CONNECTIONS
The console should only be operated with high quality screened twisted pair audio cables. All
connector shells should be of metal construction so that they provide a screen when they are
plugged into the console. All JACK connector shells should be connected to the cable screen.
All XLR connectors should have pin 1 connected to the cable screen.
ELECTRIC FIELDS
If the console is operated in an electromagnetic field that is amplitude modulated by an audio
frequency signal, the signal to noise ratio may be degraded. Degradation of up to 60dB may be
experienced under extreme conditions (3V/m, 90% modulation).

5
CONTENTS
MIDAS XL4 FUNCTIONAL DESCRIPTION
XL402 INPUT POD 6
XL401 INPUT MODULE 6
XL403 INPUT VCA FADER 8
XL412 GROUP POD 9
XL411 GROUP MODULE 9
XL413 GROUP VCA FADER 10
XL422 MASTER POD 11
XL421 MASTER MODULE 11
XL413 GRANDMASTER A VCA FADER 12
XL422 COMMS POD 12
XL431 COMMS MODULE 13
XL413 GRAND MASTER B VCA FADER 14
XL422 MATRIX POD 15
XL441 MATRIX MODULE 15
XL4 MODULE OPTIONS FUNCTIONAL DESCRIPTION
XL405 STEREO INPUT POD 17
XL404 STEREO INPUT MODULE 17
XL414 GROUP MODULE 19
MIDAS XL4 CIRCUIT DESCRIPTIONS
1. EARTHING SYSTEM 21
2. POWER SUPPLY 21
3. MONO INPUT POD 23
4. MONO INPUT MODULE 24
5. STEREO INPUT POD (OPTION) 25
6. STEREO INPUT MODULE (OPTION) 26
7. GROUP MODULE (AND MIC INPUT OPTION) 28
8. MASTER MODULE 31
9. COMMS MODULE 33
10. MATRIX MODULE 35
11.20 LED METERS 37
MIDAS XL4 TECHNICAL SPECIFICATION 39
SCHEMATIC DIAGRAMS 43

6
XL4 FUNCTIONAL DESCRIPTION
XL402 Input Pod.
1. The MIC control gives continuous adjustment of the mic amp gain from + 15dB to + 70dB
2. The PAD switch gives 20dB of attenuation to the mic signal and will allow the connection of
high output microphones or line level signals. If the mic amp is transformer coupled (option) the
pad greatly reduces the risk of saturation at very low frequencies.
3. The 48V switch connects 48 volt phantom power to the mic input suitable for a condenser
microphone or DI box.
4. The LINE control gives continuous adjustment of the line amp gain from - 20dB to + 20dB
5. The LINE switch connects the line input to the signal path and disconnects the mic amplifier.
This switch is under automation control.
6. The PHASE switch activates a 180 degrees phase change on both the mic and line inputs. This
switch is under automation control.
7. The LO PASS filter control acts on the mic input only and is continuously adjustable from 1K
to 40K. When the filter is set to 40K there is no loss at 20K.
8. The HI PASS filter control acts on the mic input only and is continuously adjustable from 10Hz
to 400Hz. When the filter is set to 10Hz there is no loss at 20Hz.
9. The METER monitors the peak signal level of the input channel pre fader. When the GLOBAL
METER CHANGE OVER switch on the COMMS module is activated the meter monitors the
mic amp or line amp output (which ever is in use).
XL401 Input Module.
1. The DIRECT output control gives continuous adjustment of the direct output level from +
10dB to off. The output is derived from the input channel post fader signal.
2. The PRE FADE switch re configures the direct output to derive signal from the input channel
pre fader.
3. The PRE INS & EQ switch re configures the direct output to derive signal from the input
channel pre insert and equaliser.
4. The TREBLE (dual concentric top) control gives continuous adjustment of boost and cut from
+ 15dB to - 15dB with a 0dB centre detent.
5. The treble WIDTH (dual concentric bottom) control gives continuous adjustment of bandwidth
from 0.1 to 2 octaves with a 0.5 octave centre detent. This only operates when the BELL switch
is activated.

7
6. The treble FREQ control gives continuous adjustment of the frequency range that the treble
equaliser acts on from 1K to 20K.
7. The treble BELL switch converts the treble equaliser from traditional MIDAS shelving re-
sponse to full parametric operation.
8. The HI MID (dual concentric top) control gives continuous adjustment of boost and cut from +
15dB to - 15dB with a 0dB centre detent.
9. The hi mid WIDTH (dual concentric bottom) control gives continuous adjustment of band-
width from 0.1 to 2 octaves with a 0.5 octave centre detent.
10. The hi mid FREQ control gives continuous adjustment of the frequency range that the hi mid
equaliser acts on from 400Hz to 8K.
11. The EQ switch connects the equaliser in the input channel signal path and is under automation
control.
12. The LO MID (dual concentric top) control gives continuous adjustment of boost and cut from
+ 15dB to - 15dB with a 0dB centre detent.
13. The lo mid WIDTH (dual concentric bottom) control gives continuous adjustment of band-
width from 0.1 to 2 octaves with a 0.5 octave centre detent.
14. The lo mid FREQ control gives continuous adjustment of the frequency range that the lo mid
equaliser acts on from 100Hz to 2K.
14. The INSERT PRE EQ arranges the input channel signal to pass through the insert point
before the equaliser when activated and after the insert point when not activated.
15. The BASS (dual concentric top) control gives continuous adjustment of boost and cut from +
15dB to - 15dB with a 0dB centre detent.
16. The bass WIDTH (dual concentric bottom) control gives continuous adjustment of bandwidth
from 0.1 to 2 octaves with a 0.5 octave centre detent. This only operates when the BELL switch
is activated.
17. The bass FREQ control gives continuous adjustment of the frequency range that the bass
equaliser acts on from 20Hz to 400Hz.
18. The bass BELL switch converts the bass equaliser from traditional MIDAS shelving response
to full parametric operation.
19. The mono AUX controls (1 to 16) give continuous adjustment of the level sent from the input
channel to the aux busses. The level adjustment is from + 6dB to off.
20. The mono aux ON switches connect signals from the input channel to the mono aux busses
and are under automation control.

8
21. The mono aux PRE switches change the signal sent to the mono aux busses from post fader to
pre fader.
22. The ST AUX controls (1 to 8) give continuous adjustment of the level sent from the input
channel (post pan) to the stereo aux busses. The level adjustment is from + 6dB to off.
23. The stereo aux ON switches connect signals from the input channel to the stereo aux busses
and are under automation control.
24. The stereo aux PRE switches change the signal sent to the stereo aux busses from post fader
to pre fader whilst retaining the post pan stereo image.
25. The PAN control places the input channel within a stereo mix and has a constant power law
i.e. - 3dB at the centre position.
26. The INS switch connects the input insert return signal to the input channel before or after the
equaliser (see insert pre eq switch 14) and is under automation control.
27. The ST switch connects the input channel post fader signal to the stereo master buss via the
pan control and is under automation control.
28. The MUTE switch mutes the input channel at all points except the insert send and pre insert /
eq direct output. This switch is under automation and auto mute group control.
XL403 Input VCA Fader.
1. The SOLO switch sends the input channel signal to the PFL mono and AFL stereo busses. If
the switch is pressed for a short time it will latch on or off, but, if it is held on for more than 1
second the latching is disabled and when the switch is released the channel solo will turn off.
2. The ISOLATE switch disconnects the channel from the automation screen recall. Screen
storage is still active.
3. The SAFE switch disconnects the input channel mute from the 8 auto mute busses.
4. The GROUP ASSIGN SWITCHES 1 to 10 are under automation control and perform 3 major
functions:-
i. They are used to connect the input channel post fader signal to the 16 AUDIO groups via
the pan control.
ii. They are used to assign the input channel to the 10 VCA sub groups.
iii. They are used to assign the input channel to the 8 auto MUTE groups.
The function of these switches is globally selected by pressing the large AUDIO, VCA or MUTE
switches on the AUTOMATION CENTRAL CONTROL panel. A fourth large switch LOCK is
used to disable all the input channel group assign switches throughout the console so as to avoid
accidental operation. It is still possible to view the switch status of all three group types when in
this mode.

9
5. The VCA INPUT fader gives continuous adjustment of the input channel level from + 10dB to
off.
XL412 Group Pod.
1. The AUX switch changes the function of the left and right meters so that they monitor the aux
send outputs in place of the audio group outputs.
2. The RETURN switch changes the function of the left and right meters so that they monitor the
post fader line return signals. If the AUX switch is not activated the meters return to monitoring
the audio group outputs regardless of the RETURN switch position.
3. The METERS monitor the peak signal level of the group, aux or returns as described above
but when the GLOBAL METER CHANGE OVER switch on the COMMS module is activated
the meters monitor the group bus, aux bus or return input amplifiers ( which ever is selected ).
XL414 Group Module.
1. The AUX SEND controls give continuous adjustment of the mono aux bus output levels from
+ 10dB to off.
2. The aux send MUTE switches mute the aux bus outputs.
3. The aux send SOLO switches send mono aux bus signals to the PFL and AFL busses. If a
switch is pressed for a short time it will latch on or off, but if it is held on for more than 1 second
the latching is disabled and when the switch is released the solo will turn off.
4. The FADER CHANGE OVER switches swap the mono aux busses with the audio group
busses so that the console can be used for monitor applications.
5. The VCA GROUP switches assign the line returns to the 10 vca sub groups.
6. The TREBLE control gives continuous adjustment of boost and cut from +15dB to -15dB with
a centre detent. The frequency is fixed at 10kHz.
7. The BASS control gives continuous adjustment of boost and cut from +15dB to -15dB with a
centre detent. The frequency is fixed at 100Hz.
8. The 48V switch connects 48 Volt phantom power to the mic / line inputs as required for
condeneser mics etc.
9. The LEVEL controls give continuous adjustment of the line return levels from + 10dB to off.
10. The line return PAN controls place the line return signals within the stereo master mix and
have a constant power law i.e. -3dB at the centre position.
11. The line return MUTE switches mute the line return signals and are under automation control.
12. The line return SOLO switches send the line return signals to the mono PFL and stereo AFL

10
busses. If a switch is pressed for a short time it will latch on or off, but if it is held on for more
than 1 second the latching is disabled and when the switch is released the solo will turn off.
12. The SUB switches disconnect the line returns from the stereo master buss and route the
signals to the audio sub groups directly below without passing through the pan control.
13. The GRAND MASTER VCA switches assign the audio sub groups to the 2 grand master vca
sub groups.
14. The AUTO MUTE GROUP switches assign the audio sub groups to the 8 auto mute groups.
15. The SAFE switches disconnect the audio sub group mutes from the auto mute busses.
16. The TALK switches connect the audio sub groups to the COMMS module. When the TALK
TO GROUPS switch on the COMMS module is activated it is then able to route its oscillator,
pink noise, external input, talk mic or comms mic to the audio sub groups.
17. The INS switches connect the group insert return signals to the audio sub groups.
18. The ST switches connect the post fader audio sub group signals to the stereo master bus via
the pan controls.
19. The group PAN controls place the audio groups within the stereo master mix and have a
constant power law i.e. -3dB at the centre position.
20. The group MUTE switches mute the audio groups at all points except the insert send and are
under automation and automute group control.
21. The group SOLO switches send the group input signals to the mono PFL and stereo AFL
busses. If a switch is pressed for a short time it will latch on or off, but if it is held on for more
than 1 second the latching is disabled and when the switch is released the solo will turn off.
22. The GROUP FADERS give continuous adjustment of the audio sub group levels from + 10dB
to off.
XL413 Group VCA Fader.
1. The vca SOLO switches are used to monitor VCA sub groups by creating a corresponding
AUDIO sub group on the stereo AFL busses. All input channels and line returns that are assigned
to a specific vca sub group will be summed onto the solo busses when that vca solo is active.
Note i. If large numbers of inputs are assigned to one vca sub group, there will be a higher than
usual signal level sent to the solo busses when the vca solo is active (+ 6 to + 10 dB approx.).
Note ii. When vca solo switches are active the PFL buss also receives signals from the vca sub
group inputs but it will NOT be a true representation of the relative levels within the vca sub
group. This feature is however useful as it allows confirmation of signal present and signal quality
when the vca fader is down or the vca sub group is muted. It is therefore important to know the
status of the PFL MONITOR switch on the COMMS module before using the vca solo switches.
Note iii. If a vca solo switch is pressed for a short time it will latch on or off, but if it is held on for
more than 1 second the latching is disabled and when the switch is released the solo will turn off.