Akai AX80 Service Manual

3)
Turn off
the Memory Protect SW.
4)
Save the above
parameters
to
one
of Memory
Bank
(e.g.
Bl) and
turn ON
the Memory Protect
SW.
5)
Select any Memory
Bank
or
Preset.
Do not touch
any keys.
6)
Select the Memory Bank
again
where the above par-
ameters are saved
(e.g.
Bl).
7)
Connect the oscilloscope probe
to
IC 101 Pin 1.
8)
Set
the oscilloscope range
so
that the waveform can
be
seen clearly.
9)
Press one-octave
lower
C
key (C5) from the
highest
C
key (C6) as
the 1st key to press.
10)
Check peak-to-peak
voltage of the
waveform.
2V
Ei
....
V
\
\
\
V
S£
T
I
>
\
N
\
\
\
If
\ V
Jl
^1
Fig.
7-2
Output waveform when
C5
is
depressed.
1
1)
Connect the
oscilloscope
probe
to
Pin 1
of the fol-
lowing ICs
and read
peak-to-peak
voltages.
Key
No.
ICNo.
2nd key
D5
IC201
3rd key
E5
IC301
4th key F5
IC401
5th key
G5
IC501
6th
key
A5
IC601
7th key B5
IC701
8th key C6
IC801
*
Key numbers are indicated
as the
FREQ RANGE
at
"16"
setting (See Fig. 4-1).
'PICAU
Fig.
7-3
Output
waveform when
C6 is
depressed.
12)
Determine
the
average peak-to-peak voltage
(i.e.
lOVp-p) from
above readings.
13)
Connect
the oscilloscope probe to IC101 Pin 1.
14)
Press the
lowest C key (CI) and read peak-to-peak
voltage, then change the connection
to
IC201
pin
1,
press the next higher key (Dl) and read Peak
to Peak
voltage
in the same manner
as the
item
1
1)
above.
1
5)
Find the
lowest
Peak-to-peak voltage and
adjust
by
turning
VR1
to that so
that this lowest peak-to-peak
voltage on this particular voice
will
be the
same as
the average peak-to-peak voltage from
the
item
12.
Fig.
7-4
Output
waveform of lowest
Peak-to-Peak voltage
16)
If
you
can not
go
back
to this voice number, simply
switch
to the other Memory Bank then
back
to
the
same
bank
as the item
6 (e.g.
Bl).
17)
Press
the lowest
C key (CI) as the
1st
key then next
higher key
until you get the voice
you
want.
18)
Adjust
VR1 as same manner
as
the
item 15.
12
SERVICE
MANUAL
AX80

Akai AX80 Specifications

General

Brand	Akai
Model	AX80
Category	Synthesizer
Language	English