Amiga Computing - Commodore Is Awesome

Case
ected
and
me, it
tenth
- no
art to
th
t
?as a
rid
you
use
to a
nd
you
!at
The pretty blue boxes indicate the
guesses (more scientifically known as
samples) which the digitising
hardware has made at certain points
on the waveform.
It can only work to a defined
resolution, which is why the points
ore not entirely accurate, For example,
if the Amiga worked with a 16 bit
resolution instead of an 8 bit
resolution, the boxes would be placed
twice as accurately.
However, 8 bit samples can still
sound pretty darn good, so let's not
start complaining.
A.M.A.S.
A Sampler is the product of the
relationship D between Nlicrodeal and
the V UK's premier sample masters, 2-
Bit A Systems.
NThe
hardware comprises of a full 8bit
C stereo sampler as do most of the
other E units, but what makes A.M.A.S
unique D is the built-in MIDI interface.
Although M MIDI interfaces for the
Amiga i can be picked up for about E20,
it's
d
a bonus having it built-in to the
sampler as you can use it in
i
conjunction with the sample editing
software.
A
More about this later.
m
The software is supplied all-in-one,
i
that is to say that one program
performs g all the functions that are
available. a It uses a series of icons for
operation and these are arranged in
the lower area of the screen. Basic
sample record and playback controls
1
All
Now we come to the meaning of the
sample rate. In this example. the
boxes are a lot thicker: the sample
rate has been reduced. There are less
samples, and even though they are
just as accurate as the previous ones
when it comes to guessing the level,
the fact that there are less means the
Amiga has less information with
which to constuct its one version of
the waveform. The less information
the Amiga has, the more attful the
sample will sound, From this it
shouldn't be hard to work out that the
more samples per waveform the better.
EEO IMMO
DEB
1IME INN
131201:1
I B M -
m•,
=Pr
WIT 4
* 11,
NEP EL
LIII - —0
3
7a
,,,, 1.
MI 0
1
Ell
NI *4
1116.11
are located in the centre of the screen
NT
SAM
and use the kind of symbols you
would find on a tape deck so that
initial operation is straight forward.
Samples are displayed in standard
form along the top of the screen. Two
sample windows are used in A.M.A.S,
one for each stereo channel with each
channel being selectable so that you
can operate on it independently of the
other. Alternatively, you can opt to
work on both channels
simultaneously,
Most of the functions, except for
disk operations, are stored on
4
•
C
O
V
E
R
S
T
O
R
Y
- =
-.2
••
-
%'
-
M-
.
7
••.
= 2 _
•
-
•
-
•1
•2.
.e•
•
t
i
ilL
The piece de la resistance: the Amiga
generated version of the waveform. This
one was constructed using a fairly high
sample rate, but you can still see that
the waveform is no longer nice and
smooth — it now has "steps". The more
samples taken, the smoller the steps.
the closer the sound to the original.
Mathematicians amongst you will be
overjoyed to learn that Shannon's
Sampling Theomm states that to
digitise a given waveform, you need to
sample it at a frequency of at least
twice that of the original waveform.
Non-mathematicians won't care.
"buttons" with icons upon them. My
complaint here is that although some
of the icons are easily recognisable
and relate to the function — the fade in
and filter symbols for example —
others do not immediately ring a bell
and so a fair bit of memory work and
manual reference is required.
Although the hardware is capable of
sampling up to 40kHz in stereo and
90kHz in mono, the software will only
sample up to 251(Hz in stereo (28kHz
mono) but is capable of playing back
at 28kHz, The sound quality of' these
samples is very good, but at 25Id-lz.
memory is precious and this sample
speed is only really suitable for short
sound effects or for people with an
8Mb Amiga.
The MIDI connections to the
sampler are via standard DIN type
plugs and sockets while audio input
can be achieved with two Phono type
connections or a 3.5mm jack plug at
line level for direct microphone input.
AMIGA COMPUTING November 2990 71