Akai 4400 Service Manual

1. PINCH WHEEL ADJUSTMENT
It is important that the pinch wheel shaft be kept
in perfect alignment with the capstan shaft. Proper
pinch wheel pressure is between 1,000 and 1,150
grams when the unit is operated at the tape speed
of 7-1/2 ips. Any deviation from this specification
will result in wow and flutter. Check pinch wheel
pressure with a spring scale, and if necessary, adjust
the pinch wheel load spring.
2. SUPPLY REEL SHAFT ASSEMBLY
ADJUSTMENT (See Fig. 8 at left)
Felt clutch material (2) is used between the lower
side of the reel table base plate (1) and the rewind
pulley (3) to protect recording tape from excessive
tension during rewind operation. To check the
amount of friction of this part, install a S-inch reel
with a 60 mm diameter tape and gently pull the end
of the tape upward with a spring scale. Adjust the
conical spring (4) so that the amount of tension
is kept between 400 and 500 grams. Other felt
clutch material (5) is attached to the supply roller
(6) to provide proper slippage during FWD and REC
operation, The procedure for checking friction of
this part is the same as the foregoing, and between
80 and 100 grams of tension gives best results.
Adjust the spring (7) just under the supply roller (6).
When the unit is set to fast forward operation, the
amount of friction will decrease to from 15 to 20
grams. Check to see whether this is satisfactory. If
not, adjust the spring plate (8) and the pressure
of the pulley (9).
Fig. 9 Fig. 10
z 3. TAKE-UP REEL SHAFT ASSEMBLY
ADJUSTMENT (See Fig. 8 at right)
Felt clutch material (2) is attached to the bottom
side of the reel table base plate (1) so that the re- *
cording tape will not stretch during fast forward
operation due to excessive tension. To check the
amount of friction of this part, install a 5-inch reel
with a 60 mm diameter tape, and gently pull the
end of tape upward with a spring scale. Adjust
the conical spring (4) so that the amount of tension
at this part is kept between 400 and 500 grams.
Other felt clutch material (10) is attached to the
take-up roller (11). This is to provide proper slippage
during FWD or REC operation, The procedure’ for
checking friction of this part is the same as the
foregoing, and between 150 and 180 grams of fric-
tion provides the best results. Adjust the spring
plate (7) just under the take-up roller (11). When
the unit is set to rewind operation, the amount of
friction of this part will decrease to from 15 to 20
grams. Check to see whether this is satisfactory. If
not, adjust the spring (12) and the pressure of the
set sleeve (13).
4. RECORDING/PLAYBACK CHANGING
MECHANISM (See Figs. 9, 10)
Turning the FWD/REC knob (N) to recording posi-
tion causes Lever (a) to pull. Recording Lever (b)
(as illustrated by dotted line), and the FWD/REC
Changing Switch (SW-9) is turned to recording posi-
tion. If Lever (a) does not pull Lever (b) properly,
Changing Switch SW-9 will not operate properly.
This may cause abnormal oscillation and inability
to record. In this case, loosen Screw (c) and adjust
lever.

Akai 4400 Specifications

General

Brand	Akai
Model	4400
Category	Tape Deck
Language	English