Kiwi Technics Kiwi-30, User Manual

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36
Test Mode
Test Mode
The Kiwi-30 is put into TEST mode
by pressing and holding the
CARTRIDGE button at the same time
as the Kiwi-30 is powered on until
'TEST MODE' shows on the display.
Note – Warm up the M30 for 30mins
to stabilize the audio path
electronics before running the
Calibration.
The 6 test modes are accessed
using the Tone buttons. During test
mode The voice that is sounding will
show on the red LED digits. There
are six short bars and when a note is
pressed a tall bar shows.
The first adjustment is the VREF.
Using an accurate DVM connect to
DG and TP2 (located to the left of L1
and the battery on the main board).
Adjust VR6 (Near L1) until the VREF
pin me4.70 volts.
Test Mode 1
This is used to calibrate the L2
Master Oscillator for DCO1.
Center
the TUNE control on the front
panel and set the global Fine Tune
to zero (0)
. Press note A4 which is
just below middle C and tune L2
using a plastic screwdriver until the
output is 442Hz. The easiest way is
to use a guitar tuner near the
speaker or you can put an
oscilloscope on the POLY OUT test
point on the MKS-30 main board.
Note - If you have to use a metal
screwdriver you need to be aware of
two things. 1) the ferrite cores are
very fragile and the top will chip
easily so use the correct sized
screwdriver and be very gentle, 2)
any metal near the ferrite will alter
the tune. So you need to move the
screwdriver well away from the ferrite
core after each adjustment.
Test Mode 2
This is similar to test mode one but
also turns on DCO2. Tune L1 near
the rear next to the battery until
minimal beating can be heard. It will
probably not possible to remove all
beating totally so get as close as you
can. These Oscillators will also drift
tiny amounts with temperature and
time and is part of the MKS-30
'charm'.
Test Mode 3
This test sets the output level for
each voice. Put a oscilloscope probe
onto the POLY OUT test point and
test each voice for the same output
level. Adjust the level to about 1.5V
peak to peak using VR2 next to the
filter. The MKS30 manual says to set
this to 600mV but we found this is
not possible on our 2 test units. The
important thing is they are all the
same level and not distorting.
Test Mode 4
DC Balance. The voices in this mode
are set to not rotate. To change to
the next voice press C2. Put a
oscilloscope probe onto the POLY
OUT test point and repeatedly press
a note for each voice and adjust VR4
labeled DCBAL for a minimal DC
change on the scope. Change to the
next voice by pressing C2.
Test Mode 5
VCF Resonance
For each voice set VR1 for 250mV
peak to peak and VR3 for 1KHz.
These trims interact and are fairly
coarse so just get as close as you
can for each voice.
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