tween all combinations of settings, and press
again to select.
TRANSFORM BANKS
Jena offers 15 banks of digital transform data.
Please refer to the online version of the manual
for a detailed list with diagrams. The first 11
banks (numbered
0
to
9
, and
a
) are wavetables
intended mostly for audio waveform genera-
tion. Each wavetable contains 256 smoothly
morphing waves that are arranged circularly
so that there is no audible step while jump-
ing from wave 255 to 0. The wavetables have
been carefully designed to suit various sound
synthesis needs. For example, bank
7
contains
smooth curves consisting of low-order Cheby-
shev polynomials (fig. 5) that are well-suited
for experiments with deep, through-zero phase
modulation, while bank
0
contains waveforms
with distinctive human speech formants.
Some banks are specifically designed for effi
-
cient warping of CV signals, like LFO waveforms
or simple envelopes. For example, bank
b
fea-
tures a simple shape that gradually morphs be-
tween linear ramp through triangle to inverted
ramp, while bank
c
introduces an increasing
number of symmetric as well as asymmetric
folds to an initially linear (1:1) transform.
A special bank
d
contains a very particular
set of waveforms. Besides being interesting
shapes, each of them is a combination of 8
so-called Walsh functions. Similar to sinu-
soids, these semi-rectangular functions (fig.
6) can be used for additive synthesis. We have
selected 256 different Walsh combinations
that are generated at the individual binary
outputs of Jena, and at the same time, their
sum with corresponding factors (A7=1/2,
A6=1/4, A5=1/8, A4=1/16… etc.) yields the
main output signal.
Bank
e
has a special purpose: it generates
drum patterns instead of waveshapes. With
this bank, the individual binary outputs of Jena
are used to produce sequences of short gate
impulses that can fire up to 8 drum voices in
your rack.
There are 256 patterns of 32 steps corre-
sponding to a single bar that may be selected
by function or waveshape controls. They are
arranged so that several consecutive positions
6
max
min
Scanning signal
Scanning signal
255
0
Output waveshape
Output waveshape
max
min
Scanning signal
Scanning signal
255
0
Output waveshape
Output waveshape
max
min
Scanning signal
Scanning signal
255
0
Output waveshape
Output waveshape
fig. 4:
distortions of wavetable sinusoid
signal resulting from inaccurate
scanning of the cycle
underscan
overscan
imperfect edge