Akai MX-550

V. ELECTRICAL ADJUSTMENT
NOTE:
1) The following adjustment should be performed in
the test mode.
To engage the test mode, connect the AC power
cord to the AC outlet while pressing the > and
“44 buttons together.
When the test mode is engaged, X1 dub lamp is
lit.
STEP ADJUSTMENT
1. TEST TAPE/INPUT SIGNAL
2.
MODE
SS
Adjustment
Part
3. CHECK POINT, ADJUSTMENT PART | ~~
4, REMARKs (¢) and RESULT (*)
™~
™ Test Point
Connector J201 fo
TEST POINT 1R e
Pin @ a TEST POINT 2
2) When performing the tape speed adjustment, 6 | TAPEII PB LEVEL (AX-650 ONLY) 5 TAPE! PB LEVEL (AX-650 ONLY) oe Tt. Pin
observe the following notes. 1. 315Hz test tape (TF-101CL) 1. 315Hz test tape (TF-101CL) 7 ase Pin ®
e Adjustment should be started more than 30 2. PLAY 2. PLAY Pin GND
seconds after the power is ON. 3. TEST POINT 1L & 1R, VR102 (L-ch) / VR152 3. TEST POINT 1L & 1R, VR101 (L-ch) / VR151 TEST PONT SL
e Adjustment should be made on X2 speed mode (R-ch) (Reh) Pin @
first then adjust normal speed mode. 4. eConnect an AC milli-voltmeter to the TEST 4. eConnect an AC milli-voltmeter to the TEST
e Adjustment should be made in the forward POINT 1L &1R. POINT 1k & 1R. DECK PCB
direction. *-6.0dBs *-6.0dBs
3) An AC milli-volt meter input should be terminated
with 20k ohms register in parallel.
2 . TAPE | NORMAL TAPE SPEED
dBs.
a Gop hla tee ape ee) Playback levels after recording are -6.0dBs
2. PLAY
3. TEST POINT 1L, VR653
4. eConnect a frequency counter to the TEST 8 | NORMAL POSITION BIAS (AX-650 ONLY)
POINT
4L.
1.
1
kHz
and
10
kHz,
-26.0
dBs
(LINE
OUT),
43,150 + 10Hz NORMAL recording test tape (UD-124).
2. REC -> PLAY
3. TEST POINT 1L & 1R, VR402 (L-ch) / VR403
3 | TAPE Il (X2) TAPE SPEED 13S rete (R-ch)
(R_ ch)
1 3 150Hz test ta - [poooche~ 4. eConnect an AC Milli-voltmeter to the TEST
. 3, pe (TF-110CT) Pios <e, Lp
2. PLAY (press the x2 DUBBING START button) Se | POINT 1L & 1R.
3. TEST POINT 1L, VR654 ~ nas 2 ‘ e Connect an audio signal generator to the TEST
4. eConnect a frequency counter to the TEST = POINT 2L & 2R and set the generator level so
o that the TEST POINT 1L & 1R levels are -26.0
POINT 1L. 8 :
*6,300 + 20Hz dBs.
Sw.
7401
Playback
level
difference
between
1kHz
and
Se 10kHz after recording is within + 0.3dB.
4 | TAPE Il! NORMAL TAPE SPEED : |
1. 3,150Hz test tape (TF-110CT) a 7 _ BIAS OSC FREQUENCY
2. PLAY 1. CrO2 type blank tape
3. TEST POINT 1L, VR652 2. REC
4. «Connect a frequency counter to the TEST DECK PCB 3. TAPE li, T401 (P102)
POINT
4L.
4.
«Connect
a
frequency
counter
between
P102
©
%*3,150 + 10Hz pin and GND.
*100.0 + 0.2kHz
SERVICE MANUAL
24
1. 1 kHz, -6.0 dBs (LINE OUT), NORMAL recording
1
TAPE
|
(X2)
TAPE
SPEED
test
tape
(UD-124)
1.
3,150Hz
test
tape
(TF-110CT)
2.
REC
+
PLAY
2.
PLAY
(press
the
x2
DUBBING
START
button)
3.
TEST
POINT
1L
&
1R,
VR351
(L-ch)
/
VR301
3.
TEST
POINT
1L,
VR651
(R-ch)
4.
eConnect
a
frequency
counter
to
the
TEST
4.
«Connect
an
AC
Milli-voltmeter
to
the
TEST
POINT
1L.
POINT
1L
&1R.
6,300 + 20 Hz
[9 | RECORDING LEVEL (AX-650 ONLY)
¢Connect an audio signai generator to the TEST
POINT 2L & 2R and set the generator level so
that the TEST POINT 1L & 1R levels are -6.0