Jx-8P Upgrade Notes; Digital Oscillators; Front Panel Buttons; Tuning - Roland Kiwi-8P User Manual

JX-8P Upgrade Notes

Digital Oscillators

Front Panel Buttons

Tuning

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The JX-8P Synthesizer
programmable dividers from a single
master oscillator to generate the
pitch of the notes. While this does
create very a stable pitch it does
create some issues.
Because the dividers are being
reprogrammed every time the pitch
for that voice changes, the leading
edge of the DCO pulse is constantly
changing in relation to the other
voices.
This is a 'feature' of the JX-8P
hardware and cannot be altered.
This is especially noticeable when
playing in Square wave with Unison
or one of the Poly multiple voice
modes as more than one voice is
playing the same pitch but the start
point of the voice waves will not be
the same. The audible result of this is
that random notes can sound 'thin'
with much of the bass portion
missing at certain
combinations. Anything that effects
the pitch of a voice
analogue feel, pitch bending, lfo
mod, Portamento etc) will change
the DCO wave voice start points and
change the sound.
All the front panel buttons on the JX-
8P have been designed without
blocking diodes. The result of this is
if you push two buttons at the same
time unintended effects happen.
In version 4+ of the Kiwi-8P program
the synth will undergo a tuning
process whenever the Kiwi-8P is
switched on.
uses Another 'feature' of this type of
oscillator is with smooth changes
between notes audible stepping
will increase
frequency. The reason for this is
the change required in the divider
ratio gets
frequencies get higher with fewer
divider steps between notes.
This will be audible on LFO, Bend,
portamento etc and the higher the
frequency and the faster the
change the worse the problem.
This is a hardware problem and
cannot be addressed
start point
(detune,
This also happens in the JX-8P
but is more obvious in the Kiwi-8P
as the display updates any switch
presses. The JX-8P does not
display many of the button or
switch changes.
This tuning fine tunes the SAW
waveform shape.
JX-8P Upgrade User Manual v130
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the higher the
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