SOUNDCRAFT LM1 (01) PDF MANUAL

The HPF switch, when depressed, puts a High Pass filter into the signal path. This removes unwanted low frequency signals. The filter’s -3dB point is at 80Hz, and the filter has a slope of 12dB/octave.

The EQ switch places the Equaliser section into the signal path.

The shelving HF control provides a maximum cut/boost of 10dB at 10kHz. The control is centre-detented at 0dB.

The MF control creates a ‘bell’ envelope which has a maximum cut/boost of 14dB at 2kHz. The control is centre-detented at 0dB.

The LF control provides a maximum boost/cut of 10dB at 100Hz. The control is centre-detented at 0dB.

The Aux 1 PRE switch routes either the pre or post-fade signal to the Auxiliary 1 Level control.

The AUX1 Level control is used to control the signal level which is sent to the Auxiliary 1 output mix. The signal can be varied between 0dB and infinite attenuation.

The AUX2 switch routes the post-fade signal into the AUX2 bus.

The S switch enables pairs of Input Modules to be used for Decoding MS to LR Stereo. The S switch must be depressed on the channel which carries the S signal. The PAN pot on each of the channels in the MS pair must be set to the centre.

In similar fashion LR stereo may be encoded to MS on the mix buses.

The mono input to the module may be positioned within the stereo image, which is carried by the Left and Right mix buses, by means of the PANorama pot.

The PFL switch routes the pre-fade signal onto the PFL mix buses (L & R). The PFL control bus is also activated.

The associated PFL LED is illuminated when the PFL switch is active.

The PEAK LED starts to illuminate when there is 6dB of headroom left.

The L-R switch routes the output from the Pan Pot (and the S matrix if selected) onto the Left and Right Main Mix buses.

The 100mm Fader provides 10dB of gain at maximum, and infinite attenuation when closed.

Two XLR connectors are provided at the rear of the Mono Input Module. The top one is for the Mic, the lower one is for the Line input.

An optional input transformer (common to mic. and line) can be fitted.

The following table shows how to set the jumpers for phantom power and T-power options:

Looking from the component side of the PCB, the four jumpers are located in an area central approx. 7cm from the top edge and 6cm from the right-hand edge of the PCB.

On Issue 4 PCBs there is an internal switch to select 48V or 12V phantom power. The +12V and J12-0V jumpers remain.

The LINE/DIN switch allows you to select a nominal level of +4dBu (when the switch is released) or a nominal level of -10dBv (when the switch is depressed).

Pressing the RHS PHASE switch will reverse the phase of the Right-hand signal.

The rotary GAIN control provides 0dB at the centre detent, and a cut/boost of 15dB at the extremes of its travel.

L position, R position, Effect:

OUT, OUT, Normal Stereo operation

OUT, IN, Right-hand signal fed to both sides

IN, OUT, Left-hand signal fed to both sides

IN, IN, A mono sum of Left and Right signals is fed to both sides

The centre-dented BALance control provides a +3dB boost to one channel and a -8dB cut to the other channel at each end of its travel.

The HPF switch, when depressed, puts a High Pass filter into the signal patch. This removes unwanted low frequency signals. The filter’s -3dB point is at 80Hz, and the filter has a slope of 12dB/octave.

The two shelving filters are in-circuit when the EQ button is depressed.

The shelving HF control provides a maximum cut/boost of 10dB at 10kHz. The control is centre-detented at 0dB.

The LF control provides a maximum boost/cut of 10dB at 100Hz. The control is centre-detented at 0dB.

The Aux 1 PRE switch routes either the pre or post-fade signal to the Auxiliary 1 Level control.

The AUX1 Level control is used to control the signal level which is sent to the Auxiliary 1 output mix. The signal can be varied between 0dB and infinite attenuation. The signal is a mono blend of L and R.

The AUX2 switch routes the post-fade signal into the AUX2 bus.

The ENC “S” switch is used for encoding LR or MS stereo. This only affects the main L-R path.

The IMAGE WIDTH pot adjusts the stereo Image width, from mono to one end of its travel, to stereo at the other end.

The PFL switch routes the pre-fade post-EQ signals onto the PFL mix buses (L & R). The PFL control bus is also activated.

The associated PFL LED is illuminated when the PFL switch is active.

The PEAK LED starts to illuminate when there is 8dB of headroom left.

The L-R switch routes the post-fader output onto the Left and Right Main Mix buses.

The 100mm Fader provides 10dB of gain at maximum, and infinite attenuation when closed.

Two female XLR connectors are provided at the rear of the Stereo Line Input Module. The connections are as follows:

Pin 1: Ground (Screen)

Pin 2: Hot (In Phase)

Pin 3: Cold (Out of Phase)

The PHANTOM POWER switch provides both microphones with a Phantom Power supply.

Pressing the RHS PHASE switch will reverse the phase of the Right-hand signal.

The rotary GAIN control provides a gain range of 25dB to 80dB in 5dB steps.

The HPF switch, when depressed, puts a High Pass filter into the signal path. This removes unwanted low frequency signals. The filter’s -3dB point is at 80Hz, and the filter has a slope of 12dB/octave.

The EQ section is in-circuit when the EQ button is depressed.

The shelving HF control provides a maximum cut/boost of 10dB at 10kHz. The control is centre-detented at 0dB.

The MF control creates a ‘bell’ envelope which has a maximum cut/boost of 14dB at 2kHz. The Control is centre-detented at 0dB.

The LF control provides a maximum boost/cut of 10dB at 100Hz. The control is centre-detented at 0dB.

The Aux 1 PRE switch routes either the pre or post-fade signal to the Auxiliary 1 Level control.

The AUX1 Level control is used to control the signal level which is sent to the Auxiliary 1 output mix. The signal can be varied between 0dB and infinite attenuation. The signal is a mono blend of L & R.

The AUX2 switch routes the post-fade signal into the AUX2 bus.

The ‘S’ switch is used for decoding MS to LR Stereo.

The WIDTH/BAL pot has two functions: if you are using the input for LR stereo, the WIDTH/BAL pot is a balance control; if you are decoding MS microphones to LR stereo then the WIDTH/BAL pot controls the width of the stereo image, from mono when the control is anti clockwise, to enhanced stereo separation when it is fully clockwise. The balance range is +/-15dB.

The PFL switch routes the pre-fade post-EQ signals onto the PFL mix buses (L & R). The PFL control bus is also activated.

The associated PFL LED is illuminated when the PFL switch is active.

The PEAK LED starts to illuminate when there is 8dB of headroom left.

The L-R switch routes the post-fader output onto the Left and Right Main Mix buses.

The 100mm Fader provides 10dB of gain at maximum, and infinite attenuation when closed.

Two female XLR connectors are provided at the rear of the Stereo Microphone Input Module. The connections are as follows:

Pin 1: Ground (Screen)

Pin 2: Hot (In Phase)

Pin 3: Cold (Out of Phase)

The LOW BATTERY LED will flash when the battery voltage is too low. Typically 20-30 minutes of usable life remains at the onset of flashing.

The METER ILLUM switch allows the meters to be lit. Use of this facility will, of course, increase the drain on the battery.

The BATT CHECK switch allows the battery voltage to be monitored on the top (L) meter.

Two rear-mounted Sifam PPM or VU meters are fitted as standard.

Meter sources are selected in pairs by a bank of three interlocking switches:

Aux: Upper = Mono Output, Lower = Auxiliary Output.

L-R: The Main Output is monitored. Upper = Left, Lower = Right.

Monitor: This switch allows the source selected on the Monitor Panel to be metered.

A PFL from any of the input modules will over-ride any meter display. The PFL LED illuminates to indicate a PFL. The headphones will also be switched to follow any PFL signal.

When the TONE switch is depressed the main mix L & R output signals are replaced by a 1kHz tone. The Auxiliary Outputs are not affected.

The S switch connects an MS matrix into the post-fade L and R output paths. This converts LR to MS format, and vice-versa. Note that this matrix is separate from those used by the input modules.

The LIMITER switch places a level limiter in each of the Main Outputs (L & R).

The LIMIT LEDS illuminate when their respective Outputs are being limited.

The Limiter threshold is settable by Internal jumpers, the options are: +4, +6 or +8dBu (the default is +8dBu). The Attack and Release times are 2msec and 300msec. respectively.

The limiter pair may be linked together via the LINK switch. This is to provide tracking during stereo operation.

The Left Fader controls the level of the Left Output.

The Right Fader controls the level of the Right Output.

The AUX 1 Fader controls the level of the Aux 1 Output mix.

The AUX 2 Fader controls the level of the Aux 2 Output mix.

The four major outputs (L, R, Aux1 and Aux2) are electronically balanced. Optional 1:1 output transformers can be fitted to provide electrical isolation. These are easily fitted to the internal motherboard.

There are 6 jumpers: they are arranged in 2 groups of 3 jumpers. They set the limiter threshold to +4, +6 or +8dBu. Ensure that both groups of jumpers are set in accordance with each other.

Looking from the component side of the PCB, the first group of jumpers is located approximately 3cm from the top edge and 6cm from the right-hand edge of the PCB.

The second group is approximately 6cm from the top and 10cm from the right-hand edge of the PCB.

There are four 3-pin XLR male connectors on the Master Module rearcon panel. These are OUTPUT L, OUTPUT R, AUX1 and AUX2.

EXT1 is a stereo pair of balanced inputs accessed by separate Left and Right Jack sockets on the rear connector panel; EXT2 is similar.

AUX1 routes the Aux 1 mix to the Left and Right sides of the Monitor and Headphone paths; AUX2 is similar.

The L switch feeds the main Mix Left signal to the Left and Right sides of the Monitor and Headphone paths.

The R switch feeds the main Mix Right signal to the Left and Right sides of the Monitor and Headphone paths.

The L-R switch feeds the Main Mix Left signal to the Left Monitor and Headphone path, and feeds the Main Mix Right signal to the Right paths: i.e. it allows normal monitoring of the main mix output.

The MON LEVEL control adjusts the level of the Monitor Outputs (L & R).

The ‘S’ DECode switch allows you to listen, in normal LR stereo, to MS encoded signals on the Main Mix buses.

The MONO switch links the Left and Right signals in both the Monitor and Headphones outputs.

The DIM switch attenuates the Monitor outputs by a nominal 20dB. The Headphone output is not affected.

The level of the Headphones Output is adjusted by the PHONES control.

The level of Return Talkback signal is adjusted via the RTN TALK control. The output signal from the RTN TALK pot is fed into the stereo PFL mix buses. An associated logic control input enables the Return Talkback signal (together with any PFL from the Inputs) to replace the Monitor path to the Headphones.

The signal from the Inbuilt Mic is amplified by a preamplifier whose gain is adjusted by the T/B MIC GAIN control.

The output of the preamp is then passed to the TALK TO routing switches which operate as follows:

The L-R switch routes the signal to the Main Mix buses.

The EXT switch routes the signal to the COMMS connector on the rear connector panel.

The SLATE switch routes the signal to the Main Mix buses and also routes the 32Hz tone from the Slate Oscillator to the Main Mix buses.

When EXT is not in use a mono mix of the monitor signal is sent to the COMMS connector.

This can be removed by cutting the link, “OPT1”.

Looking from the component side of the monitor PCB, the link, “OPT1” is located approx. 4cm from the top edge, and 5.5cm from the right-hand edge of the PCB.

There are two associated 3-pin XLR male connectors on the Master Module rearcon panel. They are the MNTR (Monitor) LEFT and MNTR RIGHT.

There are 4 1/4″jack sockets, these provide for inputs for the EXT MNTR1 and EXT MNTR2 L and R signals.

There is a further 1/4″ jack socket for the headphones.

There is a 4-pin connector (DC POWER) for connection to the mains power supply.

There is a 6-pin connector (COMMS) to provide talkback facilities. The connections are as follows:

pin1 Talk O/P-Line-Level Output

pin2 Chassis Gnd

pin3 System Gnd

pin4 Rtn+Balanced Return Talkback Input

pin5 Rtn – Balanced Return Talkback Input

pin6 Rtn Control -Active-Low input -Connect a switch between pin 6 and 2

There are, finally, two screw post connectors for CHASSIS and for SYSTEM GROUND.

+0.0, -1dB 20 Hz to 20kHz (Mic Input to Main Output, 70dB Gain)

(All measurements at +18dBu output level) Mic/Line Input to Main Output (Faders at 0dB)

<0.003% (20Hz-20kHz)

Microphone Input E.I.N: <-128dBu (150Ω source)

Main Bus Output Noise: <-80dBu (6 Input desk, 1 channel open at 0dB)

Aux Bus Output Noise: <-80dB (6 Input desk, 1 channel open at 0dB)

Channel Fader Attenuation: >90dB (80dB at 10 kHz)

Channel Routing Isolation: >90dB (80dB at 10 kHz)

Aux 1 Send Attenuation: >90dB (80dB at 10 kHz)

Microphone Input: >1.5KΩ Balanced (1kHz)

Line Input: >15KΩ Balanced (1kHz)

L,R,Aux1,Aux2 Outputs: <80Ω Balanced

Microphone Max Input Level: +6dBu (30dB above nominal level)

Line Max Input Level: +40dBu (30dB above nominal level)

All Balanced Outputs: +24dBu

Headphones: +16dBu into 600Ω

-25dBu to -80dBu, switched in 5dBu steps

+10dBu to -35dBu, switched in 5dBu steps

+15dBu to -15dBu (Line switch out)

+5dBu to -25dBu (Line switch in)

+4dBu for 0VU

1) Fresh or fully charged battery cells

2) Limiters out

3) Measurements taken with calibrated Neutrik TP401

4) Electronically balanced Input/Output