INTRODUCTION TO THE XB-14

Background overview:

The Allen & Heath XB-14 mixer has been carefully and lovingly designed in the beautiful county of Cornwall in the UK and is manufactured alongside a wide range of professional audio mixing consoles.  Many of the components used in the XB-14 are exactly the same as in the larger Allen & Heath products and the construction methods are also very similar utilising individual vertically mounted channel circuit boards with each rotary control fixed with a metal nut to the front panel. This provides a very robust product that will resist damage and give years of reliable use. It also makes servicing much easier should it be required, with the ability to remove one particular channel from the mixer at a time, or easily change a fader.

The audio circuitry is based on years of continual development and refinement , the performance of all the elements within the mixer scrutinised and perfected to ensure the very best sound quality possible.

Multi-application:

The XB-14 is great for a range of applications from small radio or internet broadcast studios, or for larger studios with multiple rooms, for hospital radio, university radio and community radio broadcast applications. The XB-14 has a wealth of features specifically designed  for broadcasters, things like telephone communication modules for telephone callers, mic fader start sensing for external connection and internal automatic muting of the speaker outputs, stereo channel start/cue outputs for CD deck transport control, separate headphones mix & outputs for guests, an audition bus…. The list goes on!

Mic/Line Pre-amps:

The XB-14 pre-amps use a two stage design, with carefully controlled amounts of gain in each stage. When amplifying the signal from the XLR input, the gain range is huge (69dB of range to be exact) and is very evenly distributed around the gain control, meaning better control of signal level. Most of the gain comes from the first stage, so unwanted noise is kept to a minimum. There is no “pad” switch, or pad circuit — line level signals are simply plugged into the second stage of the pre-amp by using the line input jack socket. This has the great advantage of lower noise when using the line input. (It is common to attenuate line level signals, then amplify them back up again which can give more noise or hiss).

EQ:

The XB-14 is equipped with a 3-band equaliser circuit on each mono input  which can be used to cut sibilance or mic popping or to change the tone of a presenters voice. The telco channels are fitted with a total cut high pass and low pass filter which can be used to eliminate the top or bottom end of the channel frequency response. This can be very useful when a caller is connected via a low quality telephone line. Stereo channels have high and low frequency tone controls for use with music.

AUX bus:

XB-14  has a single Auxiliary bus that can be used for external processing, effects, recording or auditioning.

MIX B:

A separate stereo mix bus is provided for recording an independent mix to the main program mix, or creating a clean feed source with selected channels.

Audition bus:

The XB-14 has a dedicated stereo audition bus that can be used for auditioning or off air recording. Pressing the button marked AUD on the channels required, transfers the mix from the program feed over to the audition bus.

Channel signal/peak indicators:

Each channel on the XB-14 has an indicator to show if there is signal present. This is pre fader / ON switch so the operator can be aware of channels that are active. The peak LED also gives a warning if a channel is in danger of exceeding its peak level.

Remote Control:

The mono mic/line channels have fader start logic switching enabling them to control external equipment or automatically mute the speaker outputs to prevent acoustic feedback in localised or self-operated applications. The stereo channels have start & cue logic outputs available to hook up to external equipment like CD players. There are also options to mute the mono inputs remotely using an external “cough” switch or similar.

USB:

Getting audio to and from a computer easily is now a common requirement for sound and music production and broadcast applications. The way we have implemented this on XB-14 is super-flexible and super-easy! No longer do you need to fiddle around the back of your computer to get to the soundcard inputs, only to find that the levels are all wrong and noisy. Just plug in a USB lead to your XB-14, select the USB routing on the mixer and the device on your computer and that’s it! Quality audio to and from your PC or MAC.

Guest headphones:

The XB-14 has 3 headphone outputs. There is a headphones socket for the presenter/engineer with a routing matrix. There are two guest headphone outputs with a separate routing matrix. There is also a talk button for off air conversation with guests via the user selected comms mic channel.

Output matrix:

Both the operator and guest headphone outputs (and the control room speakers) have an output matrix with priority switched feeds. This means the operator could be monitoring one bus while a guest is listening to the program mix. There are many possible combinations.

Electronically balanced outputs:

The main program outputs are on XLR connectors with an electronically balanced output circuit.

Self operation or Producer operated:

Whether you need a mixer for a self operated broadcast situation, or whether you have a separate studio and engineer, the XB-14 has the features to fit. Separate monitor mixes can be created for operator and guests or presenter so the engineer can check levels and cue sources while the presenter or guest can listen to a different source. The engineer/producer can communicate to the guest or presenter using the Talk feature, as well as off-air communication to telephone callers.

There is also the facility for remote control of channel mutes from the studio using the remote interface connectors, ideal for studio situated mute switches.

MONO INPUT CHANNEL

Mic Input Socket

Standard 3-Pin XLR socket wired as Pin 1=Chassis, Pin 2=hot (+), Pin 3=Cold (-).

Line Input Jack Socket

Standard 1/4” (6.25mm) Jack socket for balanced or unbalanced line level signals. Wired Tip=Hot (+),  Ring=cold (-), Sleeve=Chassis.

The Line input overrides the Mic input, so if you want to hear something plugged in to the xlr socket, make sure nothing is plugged into the Line input.

Insert Jack Socket

Standard 1/4” (6.25mm) Jack socket for unbalanced insert send and return signals. Wired Tip=send, Ring=return, Sleeve=Chassis. Nominal level is 0dBu. The insert point is after the 100Hz filter and before the EQ.

Gain Control

This adjusts the gain of the input amplifier to match the signal level of the input. The gain is varied from –6dB (attenuation) to +63dB for signals plugged in to the xlr socket (Mic Input) and –10dB to +26dB for signals plugged into the Line input jack.

100Hz High Pass Filter

The Hi-pass filter is used for reducing pop noise and rumble from microphone signals. It is a 2-pole (12dB per octave) filter with a corner frequency set at 100Hz.

The filter affects signals from both Mic XLR and Line jack socket.  

HF EQ

The HF (High Frequency) equaliser affects the frequency response of the higher audible frequencies. The corner frequency of 12kHz is around 3dB from the maximum cut or boost of the circuit. It has plenty of gain and actually gives slightly more that the +/-15dB legend suggests.

MF EQ

The MF (Mid Frequency) equaliser affects the middle of the audible frequency range. The frequency graduations on the sweep control are the centre frequencies of the EQ. The range has been carefully chosen to cover “boomy” frequencies around 120Hz to 250Hz which may need cutting back, or a lift at 2 to 3kHz may be required for microphone intelligibility.  

LF EQ

The LF (Low Frequency) equaliser affects the response at the low end of the audio range. The graph shows the response of the LF EQ at maximum cut and boost. The corner frequency is 80Hz.

Aux

This control sends a signal to an auxiliary bus. The signal is sourced pre-fade or post-fade depending on the PRE switch position. The pre-fade source selection will be affected by the channel ON/OFF switch if active. The send control varies the signal level to the bus from off (fully attenuated) to +6dB, with unity gain at the arrow.

MIX B

The MIX B switch routes the channel signal to a stereo bus which is independent of the main PGM (program) bus. The signal is post-fade and follows the PAN control. The MIX B bus can be used for creating mixes for recording or clean-feed sources for external equipment.

PAN

The pan control adjusts how the signal from the mono input channel is shared between the left and right sides of the PGM, Audition and MIX B bus.  Set to the mid position, equal amounts of signal are fed to left and right, with pan set to L, none is sent to the Right bus.

AUDITION

Pressing the audition button illuminates the red LED and switches the signal from the program bus to the audition bus. The signal is post fade and follows the PAN control. The AUD switch is after the MIX B switch in the signal chain and so has no effect on the MIX B selection.

ON Switch

This mechanically latching switch operates the channel mute circuitry, turning the signal to the PGM, Audition, MIX B and Aux buses on or off.

The switch is illuminated green when pressed.

There is an option to disable the switch (make permanently ON) using the option switches on the rear-panel. If this is activated, then the switch will be illuminated green regardless of whether it is pressed or not.

There is also a remote mute option wired to a D type connector on the rear panel. When this is wired and operated the REM MUTE red LED illuminates and the mute circuit is activated regardless of whether the ON switch is pressed.

SIGNAL & PEAK LEDs

The Signal LED illuminates when the pre-fader signal level is above –15dB.

The Peak LED illuminates and stays on for around 0.5 seconds when a peak level is detected (pre-fader signal) within 5dB of clipping.

PFL Switch

The PFL (Pre-Fade Listen) switch sends the channel signal to the PFL bus and subsequently to the headphones/CRM speakers  and the main L R meters. Used for checking the audio signal before raising the fader or un-muting the channel.

Fader

The 100mm fader controls the level of the channel signal to the left & right PGM bus, Audition bus, MIX B bus and post fade Aux.

The Mono channel faders have Fader Start switching logic available to either interface to external equipment or activate the muting circuit for the control room speaker outputs.

TELCO CHANNELS

TEL IN

The Telephone Communication channel input XLR socket. Wired as Pin 1=Chassis, Pin 2=hot (+), Pin 3=Cold (-).

CLF OUT

Standard XLR output connector for the Clean-Feed output from the Telephone Communication channel.

Wired Pin 1=Chassis, Pin 2=hot (+), Pin 3=Cold (impedance balanced ground).

TELCO Input Gain

The Telephone Communication channel input gain control. Varies the gain applied to the TELCO input channel from –10dB to +26dB.

TELCO Channel Filters

The TELCO Channel has a high pass and low pass total cut filter which is designed to allow the user to reduce the frequency range of the channel when used with a telephone caller.

The high pass filter can be varied from 20Hz (full range) to 6kHz. The low pass filter from 20kHz (full range) to 700Hz.

The default position (full range frequency response) is shown.

TALK

The TALK switch enables the presenter or operator to communicate with the telephone caller with the presenters channel fader down so the presenters voice does not go to the program mix.

The source for the TALK signal is one of the mono channels, pre-selected by links set within the XB-14, the factory default is mono channel 1. The signal source is pre-fade and pre-mute on the selected mono channel.

CLF SCE

The Clean-Feed Source switch selects the signal source for the TELCO cleanfeed output. With both buttons in the up position the signal will be the entire program (PGM) mix (pre main PGM fader) but without the signal from the input on that TELCO channel, so the caller does not hear any distracting echo of their voice.

If the AUX or AUDITION switch is pressed, the TELCO clean feed signal is sourced from the selected bus, but minus the signal sent from that TELCO channel.

This is a really useful feature that can enable the operator to send a mix of signals from different channels to the telephone caller, the sources may be on or off air because the sources for the AUX bus can be pre or post fader or the Audition bus can be used.

In addition, The telephone conversation could be recorded off air using the audition or aux buses, and replayed at a later time.

AUX

This control sends a signal to an auxiliary bus. The signal is sourced pre-fade or post-fade depending on the PRE switch position. The pre-fade source selection will be affected by the channel ON/OFF switch if active. The send control varies the signal level to the bus from off (fully attenuated) to +6dB, with unity gain at the arrow.

MIX B

The MIX B switch routes the channel signal to a stereo bus which is independent of the main PGM (program) and audition buses. The signal is post-fade and follows the PAN control. The MIX B bus can be used for creating mixes for recording or clean-feed sources for external equipment.

PAN

The pan control adjusts how the signal from the TELCO input channel is shared between the left and right sides of the PGM, audition and MIX B buses.  Set to the mid position, equal amounts of signal are fed to left and right, with pan set to L, none is sent to the Right bus.

AUDITION Switch

Pressing the audition button illuminates the red LED and switches the signal from the program bus to the audition bus. The signal is post fade and follows the PAN control. The AUD switch is after the MIX B switch in the signal chain and so has no effect on the MIX B selection.

ON Switch

This mechanically latching switch operates the channel mute circuitry, turning the signal to the PGM, Audition, MIX B and Aux buses on or off.

The switch is illuminated green when pressed.

There is an option to disable the switch (make permanently ON) using the option switches on the rear-panel. If this is activated, then the switch will be illuminated green regardless of whether it is pressed or not.

There is also a remote mute option wired to a D type connector on the rear panel. When this is wired and operated the REM MUTE red LED illuminates and the mute circuit is activated regardless of whether the ON switch is pressed.

SIGNAL & PEAK LEDs

The Signal LED illuminates when the pre-fader signal level is above –15dB.

The Peak LED illuminates and stays on for around 0.5 seconds when a peak level is detected (pre-fader signal) within 5dB of clipping.

PFL Switch

The PFL (Pre-Fade Listen) switch sends the channel signal to the PFL bus and subsequently to the headphones/CRM speakers and the main L R meters. Used for checking the audio signal before raising the fader or switching on the channel or raising the fader.

Fader

The 100mm fader controls the level of the TELCO channel signal to the left & right PGM bus, MIX B bus and post fade Aux.

The TELCO channel faders have fader start switching logic signals available on the rear-panel remote interface connectors for control of external equipment.

STEREO INPUT CHANNELS ST1 & ST2

ST2 Inputs

Standard RCA phono sockets for ST2 L & R inputs.

Unbalanced. Nominal input level = 0dBu.

ST1 Inputs

Standard 1/4” jack sockets for input signals to ST1 L & R inputs.

Wired Tip=Hot(+),  Ring=cold (-), Sleeve=Chassis.

Fully balanced. Nominal input level = 0dBu.

Stereo source selector switch

Selects either ST1 or ST2 stereo inputs to the stereo channel ST1.

Allows the user to select between multiple stereo sources connected to the XB-14.

A green LED will illuminate to show which input is selected.

Stereo input level controls

For adjustment of the stereo input levels from fully attenuated to +15dB of gain.

Stereo channel EQ

The stereo channel EQ is 2 band with corner frequencies of 12kHz for the HF and 80Hz for the LF.

AUX

This control sends a signal to an auxiliary bus. The signal is sourced pre-fade or post-fade depending on the PRE switch position and is a combined sum of the left and right stereo signals. The pre-fade source selection will be affected by the channel ON/OFF switch if active. The send control varies the signal level to the bus from off (fully attenuated) to +6dB, with unity gain at the arrow.

MIX B

The MIX B switch routes the channel signal to a stereo bus which is independent of the main PGM (program) and audition buses. The signal is post-fade and follows the PAN control.

BAL

The balance control adjusts the relative levels of the left & right signals in the stereo input channel as they are sent to the PGM, Audition and MIX B buses.  Set to the mid position, the signals are balanced equally. With the balance control set fully anticlockwise the right channel will be fully attenuated and the left channel will increase by approximately 3.5dB.

AUDITION Switch

Pressing the audition button illuminates the red LED and switches the signal from the program bus to the audition bus. The signal is post fade and follows the PAN control. The AUD switch is after the MIX B switch in the signal chain and so has no effect on the MIX B selection.

ON (+START/CUE) switch

The stereo channel ON switch operates the stereo channel mute circuitry, turning the signals to the PGM, MIX B, Audition and Aux buses on or off.

The switch is illuminated green when pressed.

The ON switch also activates the START/CUE logic signals (for the corresponding selected input) wired to the remote interface connector on the rear panel.

There is an option to disable the mute circuit on all the stereo channels (make the channels permanently ON) using the option switches on the rear panel. This can be done for all 4 stereo channels together, retaining the illumination switching (if the ON switch is being used for Start/Cue).

It can also be done on an individual channel basis by using the STEREO INPUTS 1,2,3&4 slide switches in which case the illumination of the switch will be jammed permanently ON.

Fader

The 100mm fader controls the level of the stereo channel L & R signals to the PGM, MIX B, Audition and post fade Aux buses.

There is no fader start logic feature on the stereo channel faders.

SIGNAL & PEAK LEDs

The Signal LED illuminates when the pre-fader L or R signal level is above –15dB.

The Peak LED illuminates and stays on for around 0.5 seconds when a peak level is detected (pre-fader signal) within 5dB of clipping.

PFL Switch

Sends the summed L & R stereo channel signals to the PFL bus.

STEREO INPUT CHANNELS ST3 & 4

SIMILAR TO THE ST1 & 2 CHANNELS—THE DIFFERENCES ARE DETAILED HERE.

MIX B OUT

Standard RCA phono sockets for the MIX B bus output. The output level can be controlled by the MIX B Level control.

Nominal level = 0dBu, unbalanced.

USB RTN (ST6) level

The source for the ST6 input is from the USB audio device, in other words from an external computer. The level control varies the gain applied to the USB audio device input signal from off (fully attenuated) to +15dB.

CRM SPEAKERS outputs

Standard RCA phono sockets for connecting to either powered speakers or a stereo amplifier for the control room speakers. The output level can be controlled by the CRM Speakers Level control.

Nominal level = 0dBu, unbalanced.

USB audio send & return

The USB connection uses a USB1.1 compliant stereo USB audio CODEC which is also fully compliant with USB 2.

The connector is a standard USB “B Type” connector.

When connected to a computer (Windows or Mac) you will be able to transfer stereo audio to and from the XB-14.

The signal source for the send is selected using the switches below the USB connector.

If all switches are un-pressed, the post-fader main program mix will be sent to the USB output. The priority switch matrix also gives the choice of post level MIX B, post level audition bus and AUX (left hand channel) and mono program feed (right hand channel).

The USB audio input can be selected to feed the stereo channel 4 (ST4) by selecting the stereo input 6 (ST6) to that channel.

MASTER SECTION

Audition Out

Standard RCA phono sockets for the Audition bus output. The output level can be controlled by the AUD Level control.

Nominal level = 0dBu, unbalanced.

External Monitor Input

Standard RCA phono sockets for a stereo signal which can be routed to either the engineers’ CRM monitor headphones & speakers, or the guest headphones. It can be used for monitoring the program transmission or switching any external stereo source to the engineers or guests monitors.

The input level can be controlled with the EX MON level control.

Nominal level = 0dBu, unbalanced.

Main PGM Inserts

Standard 1/4” (6.25mm) Jack socket for unbalanced insert send and return signals.

Wired Tip=send, Ring=return, Sleeve=Chassis. Nominal level is 0dBu.

The insert point is pre the main PGM fader.

Main PGM Outputs

Standard XLR output connector for the main program mix left & right outputs.

Wired Pin 1=Chassis, Pin 2=hot (+), Pin 3=Cold (-).

Electronically balanced, nominal level = +4dBu (=0VU).

AUX Output

Standard 1/4” (6.25mm) Jack socket for aux output.

Wired Tip=Hot (+),  Ring=cold (-), Sleeve=Chassis. Impedance balanced. Nominal level = 0dBu.

Mono Output

Standard RCA phono socket for the Mono PGM bus output.

The mono program bus is Nominal level = 0dBu, unbalanced.

The PGM mono output is a mono version of the main PGM stereo out but is independent of the main fader.

Headphone Output Sockets

Standard 1/4” (6.25mm) Jack sockets for the engineer/self operator and two guests.

Wired Tip=Left (+),  Ring=Right (-), Sleeve=Ground.

⚠ Warning
To avoid damage to your hearing do not operate the headphones or sound system at excessively high volume.  Continued exposure to high volume sound can cause frequency selective or wide range hearing loss.

48v Phantom Power switch

Press this in to switch 48v Phantom Power to the 4 Mic input xlr connectors, if any of the microphones attached require power.

Dynamic microphones won’t mind  being connected to a phantom powered input, but care is needed to ensure that 48v is not switched on if an xlr is used to input a signal from an electronic circuit (ie. Another mixer or keyboard).

When switching 48v on or off, or plugging in connectors to channels with 48v present, it is important (and normal procedure) to mute the channels. This will avoid loud clicks and bangs potentially getting through to the amps & speakers with the possible effect of damaging the speakers, or the audience’s hearing!

Main Left & Right meters

12 segment LED meters, peak type response, the “0” position reflects nominal level at the outputs (+4dBu from the main PGM outputs). The meters display the  signals from the CRM + Phones selector switches below, or the  PFL (pre-fade listen) signal from any selected channels, which overrides.

PFL Active LED

Illuminates red when any one or more PFL (pre-fade listen) switch is pressed. Indicates that the meters are displaying the PFL signal rather than the signal from the selected source.

CRM + PHONES Source Selector switches

These 5 switches select the signal source for the control room speakers, headphones monitor and the meters. They work on a priority basis. If they are all up then the post-fade main PGM signals will feed the monitor circuit, if any of the switches are pressed then the PGM signal will be replaced. If more than one switch is pressed the switch nearest the meters will take priority.

The PFL signal will override the selection to the meters and CRM if activated.

GUEST PHONES Source Selector switches

Similar to the CRM + PHONES selection switches, these select the source for the guest headphones output. The choices are the same as for the CRM outputs, but a different source can be selected for the guests to that selected for the operator.

The PFL signal will not be fed to the guest phones outputs unless the PFL ENABLE TO GUEST switch is pressed. This is an under-panel switch so it cannot be operated accidentally.

TALK TO GUEST switch

Pressing this switch allows the microphone channel that has been selected as the comms channel, to speak to the guest headphone feed. If the guest is listening to the program mix, for example, this will reduce in volume to a background level when the talk switch is pressed.

CRM Speakers level

Adjusts the level of the signal to the control room speaker outputs from off (fully attenuated) to unity gain.

DIM & Cut CRM Speakers

The Dim switch reduces the level of the control room speakers by 20dB.

The Cut CRM Speakers LED illuminates red when the control room speakers mute circuit is activated, either by external switching using the remote interface or by raising any one of the mono channel faders (if the MIC FADER UP switch has been pressed).

MIC FADER UP = CUT Speakers

An under-panel switch to enable the fader start logic switching to cut the control room speaker outputs. This is useful when the CRM speakers are in close proximity to the microphones plugged into the mono channels and acoustic feedback may occur from the speakers to the microphones.

Press the switch to enable the automatic muting.

Control Room Phones level

Adjusts the level of the operators’ control room headphones from off (fully attenuated) to maximum. The headphone amplifier has a gain of 12dB.

Guest Phones level

Adjusts the level of the guests’ headphones from off (fully attenuated) to maximum.

Each headphone output socket has a dedicated amplifier with a gain of 12dB.

EX MON level

This is the master level control for the external monitor stereo input.

The range of adjustment is from off (fully attenuated) to unity gain.

MIX B level

This is the master level control for the MIX B stereo bus output.

The range of adjustment is from off (fully attenuated) to unity gain.

AUD level

This is the master level control for the audition stereo bus output.

The range of adjustment is from off (fully attenuated) to unity gain.

Program Mix Fader

The main program mix level control. Affects the stereo PGM output, but not the mono PGM output.

0dB, or unity gain is at the top of the fader.

REMOTE INTERFACE CONNECTORS

Start/Cue logic

The Start/Cue logic from the Stereo channel ON switches is designed to interface to a common standard employed by Denon and Pioneer equipment. The logic signals are usually wired to a 2 pole 3.5mm jack plug where a low pulse on the tip starts the deck and a low pulse on the sleeve stops or cues the deck. There needs to be some form of ground connection between the equipment for this to work—normally effected by the audio connector leads.

Notice that there are Start/Cue outputs for 7 machines even though there are only 4 Stereo channel ON switches. That’s because there are dual inputs on 3 of the stereo channels making a total of 7 sources and the XB-14 only sends a Start/Cue signal to the deck selected as a source to the channel whose switch is pressed. It’s clever like that!

External Meter socket

This can be used to feed the main Program PGM L & R signals to external metering equipment. These are line level analogue signals, the level at 0VU will be 0dBu.

+/- 15V power is also available to power meter circuits, current draw should be kept under 100mA or so.

ON SWITCH OPTIONS

Configuration Switches

The tiny slide switches accessible on the rear panel are for configuring the XB-14’s channel ON switches. In the up position, the channel ON switch will act as a normal ON/OFF switch affecting the channel signal accordingly. If the slide switch is moved down to the “ON” position, then the corresponding channel’s ON switch will be disabled (made so that it is jammed ON). The green LEDs in the switch will then permanently illuminate. UNLESS….

Unless you are using the Stereo channel ON switches for transport Start/Cue and would like the channel mute circuit disabled but the switch illumination still to follow the switch position. In this case use the last switch in the row to disable the mute circuit on all 4 stereo channels, but make the illumination follow the switch position.

If you want, you can disable the Stereo channel mute circuit on an individual channel basis using the Stereo Inputs 1,2,3 & 4 slide switches individually. This will make the channel permanently on and the switch illumination also permanently on.

This may seem like a fussy complication, but could be useful if you want to revert to basic operation, where only the faders control the signal going out on air, disabling the ON switches so the operator cannot turn off the channel accidentally, but still want the switch illumination on certain stereo channels to follow the Start/Cue on the CD player or deck.

REMOTE A Connector wiring

The REMOTE A connector is used for the “Fader Up” logic signals from the Mono and Telco channel faders. It is also used for remote muting of channels and control room speakers. An example of how these remote signals can be used is below:

REMOTE B Connector Example: CD Deck start/cue from stereo channel ON switch

USB CONNECTION

USB Audio Interface

The XB-14 is equipped with a stereo bi-directional USB 1.1 compliant audio CODEC. It is fully compliant with USB2 ports and uses standard Windows and MAC Core Audio Drivers. In other words, plug it in and your computer will find it and be able to transfer audio to and from the USB device.

You will need some form of audio software running on your computer for playback/recording or a voice over internet phone, but on a basic level, you can use your computers media player to play straight to the XB-14 device.

APPLICATION DIAGRAM

SELF OPERATION

STUDIO+CONTROL ROOM

APPLICATION TIPS: OFF-AIR CALL RECORDING

This diagram shows the basic mixer setup using the Audition bus to record an interview with a telephone caller off-air, whilst playing music through stereo channel ST1. The interview could be recorded from the Audition out phono connectors or via the USB port as shown here.

Notes:

Ensure Audition buttons are pressed and audition lights are on for the off-air channels

Switch the CLF source for the caller to Audition.

Select Audition to USB if recording to computer.

The producer can monitor either the live program or the off-air interview using the CRM selection switches.

FIXING TO A RACK OR FURNITURE

The XB-14 can be fitted to a 19” rack or incorporated into studio furniture using the optional 19” rack fixing kit.

The rack mounting kit part number is:  ZED1402-RK19

The following pictures give you an idea of how the rack fixing kit is fitted to the XB-14.

Should you decide to purchase the kit, please follow the fitting instructions provided with the kit.

SERVICE OPTIONS

⚠ Warning

These servicing instructions are for use by qualified service personnel only. To reduce the risk of electric shock do not perform any servicing other than that contained in the operating instructions unless you are qualified to do so.

The XB-14 mixer has a versatile architecture which should satisfy most applications that you may encounter without modification. However, the following internal options provide alternative settings for those applications that may demand them.

Access is required to internal assemblies. There are a mixture of pluggable jumpers, cuttable wire links and solder bridge options inside the unit that can be modified to change mixer functionality.

NOTE: We advise that the modifications below are carried out by an authorised Allen & Heath service centre. The following information is provided to give the user an idea of how the console can be modified if required.

The diagram below shows the mixer with the rear cover removed.

Modifications to the rear mounted boards are relatively straightforward and can be done in situ. Jumper options on the channel boards can also be changed with a pair of pliers or tweezers.

Cut and solder links on channel boards are best performed by removing the relevant channel beforehand.

AUX Pre ON switch / Pre fade option 
(Mono, Telco and stereo channels)

This is a cut and solder link that sets the action of the AUX pre switch when it is in the down position.

The default setting is prefade which sources the audio signal after the ON switch but before the channel fader. The option when modified sources the signal pre ON switch and post EQ.

Audition fader start option (Mono and telco channels only)

Cut and solder link. The default for this option is to disable the channel fader start signal if the audition bus button is depressed. If the fader start option is required with the audition bus then cut and re-solder this link.

Stereo channel input option (channels ST1 - 3 only)

This option enables the stereo sources for these channels to be mixed and fed into the channel together. Simply move the position of all 4 jumpers to their opposing position to enable this option.

The red gain pots can still be used to set relative levels. The green selection LEDs will both stay on to indicate that both channels are being mixed. The main channel fader now controls both inputs.

Program fader bypass (Mix PCB)

By moving the position of these 2 jumpers, the main program fader will be bypassed. This eliminates the possibility of the program fader being accidentally pulled down.

CRM / Guest additive mix option (Master & meter PCBs)

By bridging all eight solder links on the master and meter PCBs respectively, the feed selection buttons on the right hand side of the mixer are changed from priority mix to additive mix. The default setting is priority mixing where pressing a button higher up on the mixer cuts the previous signal to listen to the selected signal.

In additive mixing mode the bottom button still priority switches between the main program mix and Mix B but all other feeds are mixed in to the signal when pressed.

Mix B / Rec out solder option (Distribution PCB)

Cut and solder link. Cutting and re-soldering these 2 links changes the Mix B out phono sockets to provide a pre fader program mix for recording purposes.

Comms mic mix option (Logic PCB)

Cutting or adding wire links here determines the source of the microphone signal that is used to talk to telephone callers and studio guests with the mixer talk buttons. The signal is sourced after the channel gain pot and so is not affected by the channel faders. A single source or a mix of sources can be used. The default is M1.

Mic fader mute option (Logic PCB)

Cutting or adding wire links here selects which microphone channels will mute the control room speakers when a channel fader is raised and the corresponding ON switch depressed. The default is that all mic channels will mute the control room feed but any combination can be used.