Sansui SE 9 Service Manual

Page 4

2) When 01 is outputted from the parts R3 and R4 on the
microcomputer, the discrimination is as follows:

K3 K2 K1 K0 (Inputports)

1 1 1 1 No key input

1 1 1 o FLAT

1 1 0 1 SET

1 o 1 1 COMPENSATE (LEVELING)
0 1 1 1 ANALYZE (MEASUREMENT)

As described above, the memory switches and mode switches can
be selected by combining the inputs of the input ports K3-Ko- Fur-
ther, although no COMPENSATE switch and no ANALYZE SWitCh
are included in the input switches of Fig. 2-1, these switches are
connected to the input ports K2 and K3, and switched to "0" or
1 " in the same manner as in the switches S3 and S4.

B. Analog-to-digital converter
The A-D converter is made up of a D-A converter, DC amplifiers,
comparators and a CPU. (See Fig- 2'6-l

Fig. 2-6 -
a, 75 1 I l I
.. P2 3
si El
0 0 Pa 0 o o o
,i,- wlo~avl
4m
BC ' VJAV
T R V 3 m (o.3~9.3v)
) IaK R?
-M .
36K CPU ,
Al... iooa M. (Microcomputer)
2Av Analog SwilclKSpectrum +5v
I Analyzer/Fade Output)
~Av
l BC 1 thv
"4" '55 V yo: (o.9~9.svl
Ava.15V( R. R; Vol = Vn4- Av V0, I Vn" Av
47 '
013- sex v0, =(flilinn')-(:_:x v1") ______ (A)
R + R , R
-vw-s"4-5V Vm'[-'RI-1an)-(r:x v51) ...... (B)

1. Operations when sound field is stored into the CPU

When a digital data of binary code from 0 0 0 0" to 1 1 1 1" is
outputted from the output ports Poe-P3 on the CPU, the digital data
is converted into a DC voltage corresponding to the digital data
through the D-A converter, next amplified into an appropriate
voltage level through the DC amplifier, and then inputted into the
two comparators.

Now, when the output ports Po~ P3 are Varied from "0 0 0 0" to
1 1 1 1 with the DC voltage vi from the spectrum analyzer set at
4.8V and with the voltage Av set at 0.15V, the voltage Vn ranges ap-
proximately from 0.6 to 9.9V. When the voltage vn approches to vi
under the above-mentioned conditions, the outputs of the two com-
parators are as follows:

OVER v._Av UNDER
OUTPUT '1 OUTPUT
4.8V 5.55V>v1->0 5.25V>v,->1
4.8 4.95 >vi->0 4.65 0
4.8 4.35 1 4.05 o

The above table indicates that when Vn is 4.8V, the OVER and
UNDER outputs are both zero. The above relationship can be ex-
pressed as follows:

vi vn' + Av

vn'+Av;vi§vn-Av ............ (1)

When the above expression is satisfied, the digital data at the output
ports P0 to P3 are stored as the output data from the spectrum
analyzer. In the manner described above, frequencies from 80Hz of
L-ch (left channel) to 10kHz of R-ch (right channel) are stored in
order as the data.

When desired characteristics (desired fader position) are required to
store by depressing the SET switch and one of the MEMORY

switches 1-4, the above description is true except that the fader
voltage is applied to the comparators as the voltage vi in place of the
voltage from the spectrum analyzer.

2. Sound reproduction of data stored in CPU

There are explained below A-D converter operations to control the
fader when compensate characteristics, desirable-arranged charac-
teristics, desirable-arranged characteristics, and Sansui's message are
reproduced.

The fader is controlled 16 times in order from the lowest band
(80Hz) of L-ch to the highest band (IOkHz) of R-ch. First, a digital
data representative of fader position required to shift is fetched
from the RAM, and next inputted to one input terminal of the com-
parator. A level voltage of the fader is applied to the other input
terminal of the comparator. Since the voltage vi is compared with
vn + Av and with vn - Av through the comparators, the CPU
determines so that when 1 " is outputted from the UNDER output,
the fader can be shifted upward and when "1" is outputted from
the OVER output, the fader can be shifted downward.

In accordance with the change at the input ports R8 and R9, the CPU
contrOIs the motor so as to shift the fader and stops the motor at
the position where the expression (1) under Paragraph 2-2: vn' +
Av 2 V, Z vn' - Av is satisfied, so that the fader shift stops. In this

case, it is possible to express the voltage v,,' as follows:

v0 . . . Output port 0 0 0 0" output voltage (n = 0)
v1 . . . Output port 0 0 01 output voltage (n =1)
v15 . . . Output port 1 1 1 1 output voltage(n =15)

In other words, the voltage V" changes into 16-step voltages accord-
ing to the value of n (0 § n $15).

However, the maximum voltage is vr: max 2 x 2 x Av

because the difference in reference voltage between the two com-
parators is 2 Av.

vn' max

32
The fader can be divided into 32 steps, so that it is possible to con-
trol the fader further accurately.

Therefore, Av =

Fig. 2-7 D/A Converter

. 2" mum-1n.
R v: P:

.Zfimr-LJ-L

V" vnPo
2n
COMP NOE" a, _ cpu
(Microcomaner)
comp °VER Ra

3. Operations of D-A converters

Fig. 2-7 shows the grid-type D-A converter.

When seen from each point K0, K K2, or K3, the D-A converter
can equivalently be shown as in Fig. 2-8.

That is say, an =1?

This voltage becomes smaller half by half in proportion as it ap-
proaches to the output terminal. Therefore, the point of th be-
comes 1/23 - Vk.
Here, if V4 = v3 = v; = V] = E5 and the state of each bit is b4, b3,
b2, or bi, v0 can be expressed as follows:
_1 . 1 1 1

V0 --3-E> (b4 +2- b3 +Tb2 +?b1)
C. Operations of multiplexer
(Analog switch for spectrum analyzer voltage and fader level voltage)
The DC-like spectrum analyzer voltage and fader level voltage are

4

Page 6

2. Alarm indication when the level is not correct,
1) Output ports to be used ; R6: R7

3) In case of over-level, "1" is outputted from the output port
R6 to flash the LED.

b) In case of under-level, "1" is outputted from the 001W
port R7 to flash the LED.

3, Operation of compensation
1, Measurement of sound field

1) Output port to be used ; (Po ~ P3) (R0 ~ R4) (06,07)

2) Input port to be used : (R3, R9)
Sequence
a) 1 is outputted from the output port 06 to generate pink
noise.

b) The OUtDut of spectrum analyzer is connected to the com-
parator inputs.

c) While changing the D-A output at the output ports Po ~ P3.
the values of ports Po ~ P3 when the input ports R3 and R9
become 0" are stored into the RAM as measurement data.

d) By switching bands at the output ports R0 ~ R2, above-
mentioned all band data in L-ch can be fetched.

e) l " is outputted from the output port 07 to generate pink
noise.

f) R-ch is measured in the same procedure as explained under
items b, c, and d.

2. Operation of compensation and reproduction of Sansuis message
1) Output port to be used :(Po ~ P3) (R0 ~ R4) (R12 ~ R14)
2) Input port to be used :(R3,R9)(R10,R,R,5)

Sequence

a) The fader position data output of L-ch lowest frequency
band is connected to the comparator inputs.

"1 0 is outputted from the output ports R3 and R4.
"0 0 0" is outputted from the output ports R0, R1, and R2.

b) The memory contents of L-ch are outputted from the
output ports P0 ~ P3.

3. SELF-CHECKING FUNCTION &

c) The direction in which fader is shifted is determined by the
input ports R8 and R9.

d) The Y-axis motor is controlled by the output ports R12 and
R13- (The motor is moved up and down.)

e) The input port R15 detects that the Y-axis mechanism
reaches the uppermost or lowermost position, and stops the
Y-axis motor. (0 is outputted from the output port R13.)

f) The X-axis mechanism is moved rightward when "1" is out-
putted from the output port R14 and is stopped when l "
is detected at the input port R10. The pulse is generated by
the combination of 32-piece chassis holes (behind the fader
control knob), LEDs and phototransistors.

g) The Y-axis mechanism is controlled to rotate the fader
control knob.

h) When 0" is outputted from the comparator outputs R8
and R9, the Y-axis mechanism stops.

i) The X-axis mechanism is moved rightward.

(It takes 0.5 sec to cover one band and about 30 sec to
cover the total bands.)

1') BY repeating the above-mentioned sequence, each fader is
controlled. The X-axis mechanism is returned to the initial
position after every procedures have been completed.

C. Manual-writing of desired characteristics
1) Output ports to be used : (R0 ~ R2) (R3, R4) "0 ~ P3)
2) Input ports to be used : (R5, R9)

Sequence

3) 0 1 is outputted from the output ports R3 and R4 and
the output of the fader L-ch is inputted to the comparators.

b) By changing the data of the output ports, the input ports
R3 and R9 are checked to obtain the data. The data of
R-ch can be obtained in the same manner. Since the voltage
across the fader control knob does not fluctuate, it is pos-
sible to fetch the data readily at one time.

TROUBLE SHOOTING IN MICROPROCESSOR

3-1. Self-checking function

When some trouble occurs in the microprocessor section and there-
fore the automatic sequence (operation order) stops, the BUSY
lamp flashes, about three seconds after the stop of sequence, to indi-
cate trouble. After that, when the test pins TP17 and TP19 on the
substrate F-3504 are shorted and the PRESET button is depressed
(See the upward picture on page 12), the self-checking function of

microcomputer starts, and the memory LEDs 1-4 come on accord-
ing to the kinds of trouble.

Relationships between trouble contents and lighting LEDs

Memory LEDl : No detection of shift pulse when fader drive
mechanism moves on the X-axis.

Memory LED2 : No detection of initial motor drive position

Memory LED3 : No detection of shift pulse when fader drive
mechanism moves on the Y-axis.

Memory LED4 : Malfunction of comparators

All LEDs 1-4 : Normal CPU, but some trouble other than de~
scribed above

1)

2)

3)

4)

3-2. Points of troubleshooting

Determine the trouble spot roughly depending upon the self-
checking function of the microprocessor. When all the memory
LEDs 1-4 come on, the CPU is normal. Then check other spots.
Identify trouble conditions and trouble spots in various modes
such as sound field measurement, fader up-and-down control,
etc.

Check the microprocessor by dividing it into several blocks.
First, check that the audio equipment is normal, and check it
in the following order: input key circuit, analog switch circuit,
fader drive circuit, A-D Converter circuit, indicator circuit,
fader position detection circuit, fader drive mechanism (thread
tension, etc.)

There occurs seldom trouble withthe microcomputer except
when an excessive voltage is applied to the B-circuit or when
one of the output ports is grounded. Therefore, first check the
peripheral circuits.

Page 17

9_ PACKING LIST r-SCHEMATIC DIAGRAM-w

Part; No. Stock No. Description

1 - 91167810 Vinyo Cover FIXED PARTSlp) Fifi-m 1

2 07801400 Carton Case (Silver Model) V
07801200 Carton Case (Black Model)

3 07815400 Styrofoam Packing

1
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10. ACCESSORY LIST I
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Stock No. Description
lEX__P-AR-TST)--_----l:_ -_-_
46124500 Microphone I 5° P 43E- 7'1 I
38103300 Pin Plug Cord | - l
07767900 Rack Mounting Adaptor | y ,.;, El
M 4
(Black Model Only) I NW 5'
00462200 Binding Head Flanged Deltite Screw, l 53 u, i . I | El
4 x 16 Black (Black Model Only) : 'aL ' 2|
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46093000 Operating Instruction I J 3|
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SANSUI ELECTRIC COMPANY LTD.: 14-1, lzumi 2-chqme, Suginami-ku, Tokyo 168 Japan PHONE:I03I 323~1111lTELEX:232-2076
SANSUI ELECTRONICS CORPORATION: 1250 Valley Brook Ave. Lyndhurst, NJ. 07071 U.S.A.V
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(SM1-30l . Printed in Japan (710830M) (Stock No.3