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OVERVIEW
GS-SW012 features two low noise reference microphones amplifiers designed for
testing and comparing microphones.
There are two headphone monitoring amplifiers enabling two users to listen to the
microphone inputs. A front panel switch selects which of the two inputs is being sent
to the outputs. Rather than providing a coarse direct switch between the two inputs
when the front panel select switch is operated a quick and clean cross fade is
performed between the two microphone inputs.
The microphone inputs use the very latest digitally controlled microphone amplifiers
and gain is accurately controlled in 1dB steps. The output of the microphone amplifiers
is fed into a low noise and wide dynamic range analogue digital converter (ADC),
before being fed into a DSP for cross fade and headphone level control.
The maximum input level of the microphone amplifiers has been carefully set to be
able to 16dB, however as there are no internal compressors or limiters to
prevent unwanted artifacts for reference monitoring an analogue pad is inserted
automatically when the input gain is set to +10dB (or lower) providing a further 14dB of
input attenuation bringing the minimum gain to -4dB and the maximum microphone
input level to before cl30dB.
In addition to the two headphone outputs, a balanced analogue XLR audio output is
also provided to allow external reference loudspeakers or recording equipment to be
used.
A small front panel LCD screen is provided to show the gain settings of the two
microphone inputs. This LCD also provides indication if the input pad is enabled on an
input or not.
48V phantom power is provided by a low noise DC:DC circuit and can be turned on/ off
for each of the two inputs by front panel self indicating toggle switches.
Each of the two inputs has its own 7 LED PPM meter providing accurate level indication
of the amplifiers output. The meters have a range of -18 to +18dB with a resolution of
6dB. This is sufficient for the user to allign the levels from two different microphones.