Akai 4400 Service Manual page 11

Vi.
AMPLIFIER ADJUSTMENTS
Audio
Oscillator
Output
A || :
Line Line igh
MONITOR SW,
sw4
Fig, 15
input
Input Sensitivity
V.T.VM.
output
Fig. 13
RIGHT LINE VR
vR2
LEFT MIC VR EQUALIZER SW, Fig. 14
VRI sw2
. PLAYBACK LEVEL ADJUSTMENT
(See Figs. 13 to 16)
1) Set the Monitor switch to "TAPE" position and
Equalizer switch to 7-1/2 ips. :
2) In case of 4400D, set output VR (VR3a, b 10 KB)
to maximum, .
3) Connect a High Sensitivity V.T.V.M. to the line
output.
4) Playback a 250 Hz pre-recorded test tape at
7-1/2 ips., and adjust semi-fixed resistor VR2 and
VR2b (20 kB) to obtain a 4 dB P.B. level. (VU
meter indicates "0" VU.)
Recording Amplifier Adjustment should be made
only after Head Adjustments and Playback Am-
plifier Adjustments have been made.
RECORDING LEVEL ADJUSTMENT
(See Figs. 13 to 16)
1) Set the Monitor switch to "TAPE" position and
Equalizer switch to 7-1/2 ips.
2) Connect an Audio Frequency Oscillator to the
Jine input and High Sensitivity V.T.V.M, to the
line output.
3) Load a Scotch-111 blank tape and set recorder
to "REC" mode.
4) In case of 4400D, set output VR (VR3a,b 10 kB)
fo maximum.
5) Supply a 1,000 Hz sine wave from an Audio Fre-
quency Oscillator' and adjust the line recording
level control volumes (VR1 and VR2 50 kB)
until the line output level reaches 4 dB. (VU meter
indicates "0" VU.)
6) Set the Monitor switch to "SOURCE" position.
7) Adjust semi-fixed resistor-VR1 and WR1b (2 kB)
to obtain 4 dB recording level. (VU meter in-
dicates "0" VU.)
8) Repeat 2 times in the same way as indicated in
Items 5) to 8) above.
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