Audio Developments AD144 - Manual (Page 2)

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SCENARIO
Time was when it became necessary to update the ubiquitous AD145 PICO mixer.
Our survey showed two main requirements: as well as Audio Developments' build and
audio qualities, narrower and shorter modules were required, and the simple but
effective equaliser from PICO had to be retained. By this time, 4-track recording
equipment had begun to trickle into the marketplace (Nagra D etc), so we decided to
give the new mixer four outputs. Because of the lower noise-floor of modern digital
recorders, the level of input signals may be reduced. We have taken advantage of this
fact and lowered the slope ratio of the limiters to 7:1. By so doing, not only is signal
distortion greatly reduced, but also the artefacts associated with limiters become
much less noticeable or objectionable. Also, sixty years after the event, sound
engineers have come to realise the potential of Blumlein's M-S techniques; to this
end, facilities have been incorporated to take advantage of these techniques. The
result is AD146 - a four-output mixer.
This was followed by AD148 - edit mixer. Based on AD146, two comprehensive left
and right monitor modules have been added for editing purposes. If a mic/line module
is included for commentary or voice-over purposes, its input-gain switch can be
changed to a potentiometer, and its gain structure changed to ensure consistent level
matching with a fixed, mechanical point of reference. Unfortunately, this way of
working does reduce headroom and also compromises a mixer's noise performance.
After AD146/AD148 it was back to the drawing board. Our customers were still
demanding a two-output mixer - as a true replacement for the PICO, and with the
PICO's simplicity. Despite past assurances to the contrary, T powering is still
required. And could we incorporate auxiliaries? And could we possibly bring it to
market at 'entry level'? We have, and we have and that's MERCURY (AD147).
AD149 completes the 140 series of mixers, and has a repertoire of party tricks not to
be found in any other mixer - not even for 'ready money'. The design team
took, as its starting point, our list of all the ideas and suggestions presented to us over
the past few years. Many of these requests came from film-sound recordists - a sub-
set of recordists we have unintentionally neglected in the past.
Since the days of R & D for AD146, channel insert points suddenly became
de rigueur. It transpires that many sound engineers have experienced the power of
FLEX-EQ, our industrial-strength equaliser, and wish to be able to use it when making
original recordings.
Being latter-day converts, we have included circuitry to take full advantage of all
M-S techniques - even shuffling - in both production and post-production.
Comment [AH1]: Page: 1