Jx-10/Mks-70 Upgrade Notes; Digital Oscillators; Front Panel Buttons - Roland Kiwitechnics KIWI-SJX Manual

JX-10/MKS-70 Upgrade Notes

Digital Oscillators

Front Panel Buttons

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The JX-10 and MKS-70 Synthesizers
use 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-10/MKS-
70 hardware and cannot be altered.
This is especially noticeable when
playing in 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 start
point combinations. Anything that
effects the pitch of a voice (detune,
analogue feel, pitch bending, lfo
mod, Portamento etc) will change
the DCO wave voice start points and
change the sound.
The front panel buttons on the JX-10
have been designed
blocking diodes. The result of this is
if you push two buttons at the same
time unintended effects happen.
Another 'feature' of this type of
oscillator is with smooth changes
between notes audible stepping
will increase
frequency and the faster the
change. 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.
This also happens in the original
without JX-10 but is more obvious in the
Kiwi-SJX JX-10 version as the
display updates
presses. The Original JX-10 does
not display many of the button or
switch changes.
The MKS-70 has diodes fitted and
does not have this problem.
JX-SJX Upgrade User Manual v100
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the higher the
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any switch