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Page 9

Fault Finding Guide

Repairing a sound mixing console requires specialist skills, but basic Fault Finding is

within the scope of any user if a few basic rules are followed.

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Get to know the Block Diagram of your console (see page 32).  It is just like following
a road map.

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Get to know what each component in the system is supposed to do.

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Learn where to look for common trouble spots.
The Block Diagram (see page 32) is a representative sketch of all the components of

the console, showing how they connect together and how the signal flows through the
system.  Once you have become familiar with the various component blocks you will find

the Block Diagram quite easy to follow and you will have gained a valuable understanding
of the internal structure of the console.

Each Component has a specific function and only by getting to know what each part

is supposed to do will you be able to tell if there is a genuine fault! Many `faults’ are the
result of incorrect connection or control settings which may have been overlooked.

Basic Troubleshooting is a process of applying logical thought to the signal path

through the console and tracking down the problem by elimination.

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Swap input connections to check that the source is really present. Check both Mic
and Line inputs.

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Eliminate sections of the channel by using the insert point to re-route the signal to
other inputs that are known to be working.

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Route channels to different outputs or to auxiliary sends to identify problems on the
Master section.

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Compare a suspect channel with an adjacent channel which has been set up identical-
ly.  Use PFL and AFL to monitor the signal in each section.

All manuals and user guides at all-guides.com

Содержание SPIRIT LIVE 42

Страница 1: ...All manuals and user guides at all guides com a l l g u i d e s c o m...

Страница 2: ...ice of four Mute Groups All frame sizes are provided as standard with dedicated stereo inputs 1 stereo input is included on the 12 channel frame and 2 stereo inputs on all other frame sizes Each stere...

Страница 3: ...xible and potentially destructive feature of the mixer They have a similar effect on the frequency response of the input channel as the tone controls on a hi fi system but with much greater precision...

Страница 4: ...hen the signal becomes so high that it would exceed the power supply rail voltages and is as a result limited This commonly occurs where gain settings are incorrectly set or where sources are improper...

Страница 5: ...f the warranty please read this section carefully The LIVE 42 mixer must only be connected through the Power Supply supplied The wires in the mains lead are coloured in accordance with the following c...

Страница 6: ...Page 5 CONNECTING IT UP All manuals and user guides at all guides com a l l g u i d e s c o m...

Страница 7: ...pole mono jacks which will automatically ground the cold input Use this input for sources other than mics such as keyboards drum machines synths tape machines or guitars The input is BALANCED for low...

Страница 8: ...ck socket which is normally bypassed When a jack is inserted the signal path is broken just before the mix fader The mix signal appears on the TIP of the plug and is returned on the RING A Y lead may...

Страница 9: ...elected input if a phasing problem is suspected Grounding and Shielding For optimum performance it is vital that all signals are referenced to a solid noise free earthing point and that all signal cab...

Страница 10: ...ructure of the console Each Component has a specific function and only by getting to know what each part is supposed to do will you be able to tell if there is a genuine fault Many faults are the resu...

Страница 11: ...tion The signal from the channel appears on the TIP of the plug and is returned on the RING The insert point allows limiters compressors and other signal processing units to be added as required to pa...

Страница 12: ...its or extra loudspeaker fills AUX 1 2 3 are derived before the channel fader PRE FADE and are therefore unaffected by the fader position This makes them particularly suitable for foldback or monitor...

Страница 13: ...replaces the normal Mix L R signal The PFL AFL ON LED on the master section illuminates to warn that the headphones and the meters are now responding to the PFL AFL selection and the PFL LED on the i...

Страница 14: ...FL AFL ON LED on the master section illuminates to warn that the headphones and the meters are now responding to the PFL AFL selection and the PFL LED on the input section lights to identify the activ...

Страница 15: ...urce in the stereo image When the control is turned fully left or right you feed only that side of the signal to the mix 22 ROUTING SWITCHES The input channel signal may be routed in stereo to the mai...

Страница 16: ...B buses They should be turned fully anticlockwise when not required If required the Matrix outputs may be used to create an additional stereo output from the console and in this case the Groups may be...

Страница 17: ...ormally the Matrix Sends are derived from a mono sum of Mix L R Pressing the STEREO switch routes Mix L to Matrix A and Mix R to Matrix B to allow the Matrix outputs to be used as a separate stereo ou...

Страница 18: ...AFL signal 39 PHONES This control sets the level of the PHONES output jack 40 MONO CHECK Normally the Phones output monitors the Stereo Mix Pressing the MONO CHECK switch sums the L R outputs to check...

Страница 19: ...the correct position Initial Set Up Once you have connected up your system see the sections on connection and wiring earlier in this manual for guidance you are ready to set initial positions for the...

Страница 20: ...Channel Fader slightly until the level is out of the red segments or adjust the Master Fader Note The level of any source signal in the final output is affected by many factors principal ly the Input...

Страница 21: ...c ondary system fed from the Matrix outputs The illustration shows the flexibility of the inputs to the mixer and how the direct outputs are available as sources for a multitrack tape machine The Aux...

Страница 22: ...ddition of a voice cluster and mono fill both fed from the Matrix outputs The source for the Matrix could be the main Mix or a combination of Mix and Groups The first three Aux sends are used as mono...

Страница 23: ...ereo Inputs to the Mix may be expanded by using the Stereo Returns for sources such as keyboards and drum machines when the normal Stereo input channels are already used Additional stage foldback is p...

Страница 24: ...ment is to drive a large number of separate loudspeaker outputs for spot sound effects The Groups Mix Aux Sends and Matrix outputs are all used for this purpose Each could be provided with Graphic EQ...

Страница 25: ...n advance including fader positions and muted until required Releasing the respective Master Mute button activates the whole group Pressing the button mutes the selected channels SCENE 1 OR BAND 1 SOU...

Страница 26: ...l a larger number of input channels or to accommodate a separate mixer being used as a submixer Note that the PFL AFL monitoring and Mute buses remain separate Groups 1 4 out Slave Mixer Master MIxer...

Страница 27: ...two wires but out of phase resulting in cancellation of the interference signal clipping the onset of severe distortion in the signal path usually caused by the peak signal voltage being limited by th...

Страница 28: ...a term used to describe the orientation of the positive and negative poles of an audio connection Normally connections are made with positive to positive negative to negative and this would correct p...

Страница 29: ...ical Channel Fader Attenuation 80 dB Typical Aux Attenuation 80 dB Typical Pan Isolation 70 dB Adjacent Channel Crosstalk 85 dB FREQUENCY RESPONSE 20Hz to 20kHz 1dB T H D 10dBu Input routed to Mix 20d...

Страница 30: ...FLIGHT CASE MOUNTING The console is ideal for flight case mounting with all connectors on the top panel The end cheeks may be removed to save space in the flight case if required The example below sho...

Страница 31: ...Page All manuals and user guides at all guides com a l l g u i d e s c o m...

Страница 32: ...Page All manuals and user guides at all guides com...

Страница 33: ...O MONO CHECK MIX LEFT INSERT INSERT MIX RIGHT MIX LEFT MATRIX A OUT GROUP OUT MATRIX B OUT MATRIX A BUS MATRIX B BUS FADER MATRIX A MATRIX A MATRIX B MATRIX B A A B B FADER AUX1 AUX 2 3 5 6 SIMILAR AU...

Страница 34: ...All manuals and user guides at all guides com...

Страница 35: ...All manuals and user guides at all guides com...

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