Sumo Summing Amplifier User Manual

Page 8

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Operational Manual

Overview – The Benefits of Analogue Summing

© Audient v1.0 10/2004



Having bought the unit, you’ve probably
figured out that Sumo is a high-resolution
summing amplifier with stereo bus
compressor and peak limiter, not to
mention a handy little monitor section.
Nevertheless, here are a few more
interesting and descriptive words with
which to impress your inquisitive friends.

In essence, Sumo takes a bunch of signals
from several inputs and adds or “sums”
them together to present them to one
output. This is exactly the same process as
takes place in mixing consoles – the mix
bus sums signals from all of the channels

“But my software has a mixer. Why can’t I
just use that?” I hear you cry. Digital
summing has one crucial problem; that
the output bit depth is equal to or less
than each of the internal signals. This
means that when signals are summed,
some data must be thrown away.
Moreover the volume of data discarded in
this process increases with your track
count. It would, of course be unfair to
suggest that modern software performs
this data reduction indiscriminately or
with especially poor results, however
many engineers and producers have found
there to be something lacking in their
digital mixes – often employing an
analogue console purely to make use of its
summing bus.

So what’s so special about the mix bus on
a big console? Well… only the highest of
high end, large format consoles employ
balanced mix buses to reduce crosstalk
and fend off noise. And this is precisely
the kind of mix bus you’ll find in your
Sumo, delivering the sound of a large
format console without the huge
footprint, or price tag.

Not only is Sumo’s summing bus as clean
as a whistle, it has frighteningly high
headroom. This is particularly important
because adding signals means adding their
levels, too. The more signals you add, the
more level you’re likely to find on the sum
bus. Consequently, Sumo has been
designed to handle levels in excess of