Audio Developments AD149 - Manual (Page 25)

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An addition is the remote stop/start switch for use with suitably equipped tape
recorders, eg Nagra IVS and D. Linked with this switch is the ability to automatically
precede and terminate each recording with an ident tone - selected by a DIL switch
mounted on the right-hand PCB.
For some time now, line-up tone has proved controversial and contentious - a
veritable hornet's nest. When designing AD146 we asked our customers on which
side they would prefer interrupted/pulsed line-up tone: logically - and unanimously -
the right-hand output was requested. Since that time we have been accused of
attempting to create a 'new' standard; but have yet to receive a request for line-up
tone to the suggested new international standard (sic). AD149 is supplied with
interrupted tone on the left-hand output but can easily be changed by the end-user to
the more logical right-hand output.
The input modules have features new to the AD140 series of mixers, several of which
are unique to Audio Developments; many being taken from our list of customers’
suggestions. In particular, we have been able to accommodate the requirements of
film-sound recordists and for non-European methods of working.
Whilst electronic components continue to shrink in size, mechanical components -
and human fingers - steadfastly refuse so to do. Throughout the AD140 series,
reducing the size of modules has also reduced the panel area available for
connectors. We know that connectors mounted on side panels are totally
unacceptable, so when insert points were demanded, the only possible position for
the jack was at the top of the module fascia: at least this makes it possible to dress
insert cables along with their input and output counterparts.
Clean feeds may be switched pre or post fader and we are assured that they will only
be used when recording from microphones - enabling usage of the second module
connector for channel output.
The highly-acclaimed, discreet and discrete transformer-balanced microphone-
amplifier designed for AD146 has been incorporated into AD149's microphone/line
module. Under 'normal' circumstances, the channel fader operates around the zero
mark, giving a safety-net of 10dB, but film-sound recordists have always had their own
particular method of working, and in order to guarantee the capture of everything from
"Blow, winds, and crack your cheeks! rage! blow!" to the merest zephyr, they open
channel faders to maximum and perform any active mixing on the input-gain controls.
This maximises the dynamic range of the input amplifier but throws away the
aforementioned safety-net in the process. Unfortunately, it also reduces headroom
later in the signal path and ensures a less-than-optimum signal-to-noise ratio. It also
seems to negate the raison d’être for the linear fader.
To accommodate alternative operating methods, we have replaced our usual,
switched input-gain control with a potentiometer and added an additional safety-net in
the form of a limiter controlling the gain of the input amplifier (ALC). This limiter has,