Introduction To; Output Limiter; Remote Control - ALLEN & HEATH XB 10 User Manual

INTRODUCTION TO THE XB-10
Background overview
The Allen & Heath XB-10 mixer has been carefully and lovingly designed in the beautiful county of Cornwall in the UK and is manufac-
tured alongside a wide range of professional audio mixing consoles. Many of the components used in the XB-10 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.
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-10 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-10 has a wealth of features specifically
designed for broadcasters, things like a dedicated telco channel for telephone callers, mic channel on switch sensing for switching
external equipment and internal automatic muting of the speaker outputs, stereo channel start/cue outputs for CD deck transport
control, separate headphones mix & outputs for a guest, built in mic compressors and output limiters.... The list goes on!
Mic/Line Pre-amps:
Based on the pre-amps from the Mixwizard series, The XB-10 pre-amps use low noise discrete transistor circuitry to achieve high gain
(60dB max), low noise and good linearity.
Compressors
Each mic channel has its own compressor to constrain the dynamic range from the microphone inputs if required. Low level signals are
given a gain boost. Mid level signals are mildly compressed with a soft knee response. High level signals are limited. This automatic
compression is activated with a simple switch and indicator LED to show the level of compression.
EQ
The XB-10 is equipped with a 3-band equaliser circuit on each mono input and a 2-band EQ on the Telco & stereo channels. The fre-
quency and response of each has been carefully chosen to give the maximum performance when using the EQ on a variety of sources.

Output Limiter

The main outputs on the XB-10 are equipped with a variable limiter to ensure that the final mix to air does not exceed a pre defined
level. Back panel option switches allow the limiter to be selected or bypassed. A trim pot is used to vary the threshold. There is also
an LED on the front panel that indicates when the limiter has triggered.
Telco channel
The XB-10 has a dedicated TELCO input channel with a mix-minus return feed. The mix-minus feed can be sent from the main pro-
gram mix or using a separate aux mix. There is a talk button where an off-air conversation can be held with the caller using a user
selected comms mic channel.
By Selecting the USB input, the telco channel can be used directly from the USB connection and callers can be accessed via Skype or
similar VOIP applications. This means the use of costly hybrid units, that would normally be used to connect to the telephone system,
can be avoided.
AUX / ALT bus
The XB-10 has 2 mono buses that can be used for external processing, effects, recording or auditioning.

Remote Control

The XB-10 has a 25 way D connector on its rear panel to allow a number of extra functions.
The mic and telco channels have ON switch logic that can be used to remotely control external equipment, they can also be muted
from an external "cough" switch or similar.
The stereo channels have start and cue logic outputs that can be used to operate external equipment such as CD players. Power for
remote circuitry is also available on the rear panel and a post-fade program output is available for metering.
Allen & Heath 9 XB-10 User Guide