Akai GX-280 User manual

Gx<28O0
OPERATOR'S MANUAL
3-HEAD 3-MOTOR AUTOMATIC REVERSE
—=m™iSTEREO TAPE RECORDER
THIS MANUAL IS ALSO APPLICABLE TO
MODEL GX-280D STEREO TAPE DECK
AKAI.
-AKAIL. MANUFACTURED & DISTRIBUTED BY AKAI ELECTRIC CO., LTD./AKAI TRADING CO., LTD.

INDEX
COWTIONE co py ek SE KSA ke MEER IGS aS he OO 2
4-Track Recording & Playback System ............. 5
Stereo Recording & Playback .................. 5
Monaural Recording & Playback ................ 5
Voltage & Cycle Conversion ............ 0.06 cece 5
NM OLWARC ho edit cag ab syed evbigk Caer ebe wis tales ee 5
Cycle caine cect bho bane tead Se ous ene ean shou: 5
Operating Instructions .......................2... 6
Tape: Loaditigicc: (pi ee Raise daar ache Wee as 6
Tape Speed Selection... 2... 0.2... eee eee 6
Pause Control ease eee eee ee ee
Automatic Stop & Shut-Off ..............0. 0.2.0.0. 7
Fast Forward & Rewind ...............0. 0020004 7
Direct Function Change Control ....... . a hie Buses q
Monitoring ious ele Sa naencectig bn Sd che dk Bes 7
Remote Control... 0... ee ee es 7
Automatic & Manual Reverse Playback ............. 8
Din Tack. snccgciegt Leis hd on a ies Seca abba a how sige cdo atee! oe 8
Play back: aiscecat veh nao cack beans Oe dreh ov anaes nde 9
Stereo:Play backs 2. 30.55.5 Gad bua} datnerte arenas 9
Monaural Playback .... 0.0... ccc cece eee eee 9
RE COPING? fa.55 Stiustisuave tale ucts ond Wnahe bee Pee aaa woe we 10
ERD eo SWitehe gy ysodech ihiace hace etna Piece Co eae 4 10
Stereo Recording ..... ccc ec cece cc cee enon 10
Monaural Recording ....... 0... cece eee ee 10
Recording from an External Amplifier ........... 11
Recording froma Turntable ................... 11
Pape Dubbing 2 e004 eee See eh eo ak etc 11
Sound-On-Sound Recording .:...............00.. 12
SOuUnd. MIKINg neg is Bidston aceon bee ove nedirahed aye Fe 13
Tape Splicing & [diting ......... ce ee eee 13
Tape Brasine ac ces bch nde bb he ans Rare Ee 13
Head Demagnetizing ...... 0... cece ee eee 13
Playback using model GX-280D Tape Deck.......... 14
Stereo Playback . 6... eee eee eee 14
Monaural Playback 1.0.0... 0.0... eee eee eee 14
Technical Data oat pa oka wd Vn CARER RE Oe 15
Standard Accessoriés: 20. 0c heeds eye eee a ee HES 16

CONTROLS
Front Panel Controls
INDEX COUNTER
For use in locating positiuns un a tape. With Reset Butzon, se: Index Counter
to “0000” before beginning recording cr playback.
REEL RETAINER
SUPPLY REEL TABLE ees
RECORD INDICATOR LAMP —
Recording mode indicator lamp. When Record and Forward Butcors are
dapressed (recording mode is effected), this Record Indicator Lamp witl light.
TRACK SELECTOR BUTTONS
1-4/Sterco/3-2 Buttons show respective markings above eack button. Easy
selection of proper track for recording or playback operation.
SENSING POLE (Left)
operation, when the tape is being reversed from [ao] to Fa],
During Playha
such autamatic reverse is effected when the sensing tape (affixed to the magret-
ized (ape survace) comes in contact with thia sensing pole.
SOUND REFLECTOR
SPEAKER (Left)
TENSION ARM
Phe 'T nsion Arm not enly works to correc: tape slack, but alo stabilizes tape
specd. AAs the tape adva: zed tersicn is applied and tape vibration is
climinated.
PAUSE BUTTON pe
Convenient Jar use in lemporarily suspending tape movement during recording
or playback operativn. ‘Tuming button to right locks it ino pause position.
AUTOMATIC SHUT-OFF BUTTON
Shut-C17 Burton is linked to the Automaric ShuL-CF Lever. If Phe Autor au
this button is at depressed position, when the tape comes to the end or is
broken, the power of the entire unit is cut oll, A convenent saicty leature in
case the recorder is left unattended.
POWER SWITCH
TAPE SPEED SELECTOR BUTTONS =
7-1/2 (19 cm/s) and 3-3/4 (9.5 cm/s) Speed Selector Butions. Feather touch for
vasy selection of desired speed.
MICROPHONE RECORDING LEVEL CONTROLS
(Left/Right)
When using microphones for reccrding, acjast input with these cuntrols while
pbucrving VU Meters,
MICROPIIONE JACKS (Left/Right)
When using microphones for recording, insert microphone plugs into these
jacks, Left jack is for left channel recording and right jack for right channel
recording,
HEADPHONE JACK
LINE RECORDING LEVEL CONTROLS (Left/Right)
For use in adjusting line recordiag input level. Adjust while observing VU
Meters.
VU METERS (Left/Right)
These meters indicate revording and playback levels (Left meter, left channel
level and right meter, right channel level). Normal recording level should not
cacced white zuuc uu VU Meters (0 VU).
8.R.T. SWITCID t
Depress when using AKAI S.R/I. (Super Range ‘lape)or other make low
noise tapes.
TONE CONTROLS (Left/Right) _— a —— ee 7 —s

et
LER BIGHT
TONS
Teme Beass
/
RESET BUTTON
REEL RETAINER
Lock reels mio place with these built-in reel retainers. Pull up ol retainers
outward and turn to left or right to firmly lock reels into place.
TAKE-UP REEL TABLE
HEAD COVER
Head cover houses (from left to right) Erase, Recording, Playback ané Reverse
Playback Heads,
CAPSTAN
Transports tape at consistent speed. The (X-280 (D) employs 2 high efficiency
Servo Circuit Motor for direct capastan drive, resulting in complete tape
speed stability
SENSING POLE (Right)
Ea
cof
Fos reversing tape from direction during playback operation. Such
Automatic Reverse is effected wacn the sensing tape (previously affixed to outer
edge of tape surface) comes in contact with this sensing pole.
SOUND REFLECTOR
SPRAKER (Right)
AUTOMATIC SHUT-OFF LEVER
At the end of the tape (or when the tape is broken), the Automatic Shut-Off
Lever is released and tape movement is stopped. If the Shut-Off Button is at
depressed position, when the Automatic Lever is released. the power of the
entire unit is cut off.
PINCH WHEEL
Presses against capstan to transport tape.
REWIND BUTTON
For use in rewinding tape from right to left reel at high epeed
REVERSE BUTTON
Vor effecting Manual Reverse and Reverse Playback. Sensing tape is used for
automatic reverse,
STOP BUTTON:
Depress te stop tape Wavel (releases pinch wheel).
FORWARD BUTTON
Used to advance iape in forward direction.
Recerd Button and lorward Button.
For recording mode. depress
FAST FORWARD BUTTON
Yor advancing tape in forward direction at high speed.
KEUORD BUTTON
Vor effecting recording mode, depress thie Record Button before the Ferward
Button. Check Record Indicator Lamp to confirm recording mode.
SOUND-ON-SOUND BUTTON
Use for language study, compile a duct from a single voice, or use for any
number of other interesting Sound-On-Sound operations. Depress this button
cond and subsequent recordings (sce Sound-On-Sound section of this
manual).
for
MONTTOR SWITCH
During recording mode, when Monitor Switch is at “Tape’? position, the
signals can be monitored as the tape passes the playback head. When at
“Source” (in) position, the program source is being recorded. When erasing,
cr for private listening during plzyhace mode, Monitor Switch should be kept
at “Tape” (out) position.
VOLUME CONTROLS (Left/Right)
For adjustment of sound level during playback mode.
Fig. 1

Back Panel Controls
REMOTE CONTROL JACK
Yor connection of AKA Remote Control Unit RC-16. Enables distant remote
control of Recording, Playback, Stop, Fast Forward, Rewind, and Reverse
modes.
VOLTAGE INDICATOR PLATE
Indicates six stages of voltage (100/110/120/200/220/240 V). Set Voltage
Selector Plug so that proper area voltage appears through the cut-out window
of plug.
VOLTAGE SELECTOR PLUG
In case of necessity to change voltage, remove fuse post and plug and set
plug to proper voltage.
CYCLE CONVERSION SWITCH
This switch must be set in accordance with area power source. Set to 50 Hz or
60 Hz as required,
AC CORD
FUSE POST
When changing voltage, it is also necessary to change the fuse accordingly.
LINE OUTPUT JACK (Right)
Vor playback. connect this jack with the Tape In Jack (right) or Aux Jack (right)
of external stereo amplifier.
LINE OUTPUT JACK (Left)
For playback, connect this jack with Tape In Jack (left), or Aux Jack (Left) of
external stereo amplifier.
DIN JACK HIGH/LOW INPUT SWITCH
When using Din Jack connection, if output level of external amplifier is more
than 50 mV, set this switch to ‘High’, and if output level is less than 50 mV,
set to **Low’?,
——— DIN JACK
Enables inter-connection with an external stereo amplifier by usc of a single
Din Cord. (When using Din Cord for recording, recording level is adjusted
with MIC Record Level Controls).
LINE INPUT JACK (Left/Right)
When recording from an external tuner or record player, connect the Output
Jacks of external source to these Input Jacks.
SPEAKER JACKS (Left/Right)
SPEAKER SWITCH
Set to “NORMAL” when sound from speakers is desired, and to “MUTE”’
when sound is not desired or when using stereo headphones for private
listening.
Fig. 2

4-TRACK RECORDING & PLAYBACK SYSTEM
The GX-280(D) employs a 4-track system which can be
used for either stereo or monaural. Select desired track(s)
with the Track Selector provided on the front panel.
STEREO RECORDING & PLAYBACK
SIEREU
=] = ——
‘rack 7 E Stereo L1 “=P Track 1 a
2 R2<— 2 E R24
a 3 ff Stereo Ri => 3 Ri—
4 La 4 | La
a | SEER
Stereo recording and playback requires the simultaneous
use of two tracks. For stereo operation, set Track Selector
to STEREO position. The first stereo playback and
recording takes place on tracks 1 and 3. The second
playback takes place on tracks 2 and 4, after the machine
has been set to reverse mode or the reels have been
inverted. To record on tracks 2 and 4 invert reels.
MONAURAL RECORDING & PLAYBACK
1 eS] es |
Track 1 | Mono 1 = = O
2 4
2 O fo ci
4 2—
= BS
a | pasar | 4 C1
Track 1 Mono 1 =>
2 rl] 1 7 | |
3 3
4 2 <=
= —
Fig, 3
Monaural recording and playback track sequence is 1-4-3-2.
1. Set Track Sclector to LEFT position. The first monaural
recording and playback takes place on track 1, and the
second on track 4 after the reels have been inverted.
2. Invert reels.
3. Set Track Selector to RIGHT position. The third
monaural recording and playback lakes place on track 3,
and the fourth on track 2 after the reels have been
inverted.
Model GX-280(D) does not record in reverse direction. For reverse
playback, use sensing tape for automatic reverse or the Reverse
Button provided on the front panel for manual reverse (or invert
reels).
VOLTAGE & CYCLE CONVERSION
Fig. 4
Voltage
Your equipment is normally adjusted to operate as per
voltage and cycles printed on the rear panel of your unit.
However, the operator is requested to check the previously
set voltage and cycle setting prior to operation. If readjust-
ment is necessary, please proceed as follows :
1. Remove the Fuse Post by turning it counter-clockwise.
Remove the Voltage Selector Plug and reset to area
voltage. The Voltage Selector is a rotable plug-in type
offering six selections: 100/110/120/200/220/240 V
AC,
. Change fuse according to voltage :
(GX-280): 100 Vto 120V2A 125 V
200 V to 240 V 1.5 A 250 V
(GX-280D): 100 Vto 120 V15A125V
200 V to 240 V1A250V
Caution : Be sure to disconnect the power cord hefore attempting
to readjust the voltage. To maintain optimum perfor-
mance and to prolong the lite of your machine it is
imperative that the line voltage be held within 10%
deviation of standard area voltage.
wo
Cycles
Correct tape speed cannot be obtained if the Cycle
Conversion Switch located on rear panel is not properly set.
For 50 Hz operation, set Switch to 50 Hz, and for 60 Hz
operation, set to 60 Hz position.
[5]

OPERATING INSTRUCTIONS
Model GX-280(D) is constructed of the finest materials and
with proper care will bring you many years of musical
listening pleasure. We, therefore, strongly urge you to read
this manual thoroughly before attempting operation. The
following conditions do not necessarily show mechanical
failure of your unit. If your machine exhibits any of these
conditions check for trouble as indicated.
Loss of sensitivity or tone quality
* A.C. Power voltage lower than the voltage to which your
machine is adjusted.
* Magnetized head.
* Excessively high or low recording input level.
Machine will not record or play
* Check positions of controls, input and output con-
nections and plugs.
Incorrect tape loading.
* Machine is set to automatic shut-off or stop, or to pause
mode.
*
Irregularity in tape transport
* Oil on capstan.
* Sticky or dirty tape surface.
* Bent reels,
* Improperly loaded tape.
Will not reverse play
* Improperly affixed sensing tape.
Place the GX-280(D) on any flat horizontal surface, and
operate on either horizontal or vertical position. Do not set
anything on the top of your machine which will obstruct
the ventilator. The front panel of your recorder may
become rather hot during operation; however, this is
normal,
6)
TAPE LOADING
Fig. 5
Place a full reel of tape on Supply Reel Table and an empty
reel on the Take-up Reel Table. Thread the tape as
illustrated by the dotted line in the figure. Lock reels into
place with the reel retainers provided on reel shafts. In case
automatic shut-off is desired, be sure to thread tape
through the Automatic Shut-Off Lever.
TAPE SPEED SELECTION
RECORDING TIME
TAPE SPEED
4-TRACK STEREO 4-TRACK MONAURAL
9.5 cm/sec | 19 cm/sec 9.5 cm/sec 19 cm/sce
(3-3/4 ips) | (7-1/2 ips) | (3-3/4 ips) | (7-1/2 ips)
1800 ft 3 hours : 3
Fig. 6
The GX-280(D) operates on two tape speeds ; 19 cm/sec
(7-1/2 ips), 9.5 cm/sec (3-3/4 ips). For selection of tape
speed, simply depress ‘Tape Speed Button according to the
required speed.

PAUSE CONTROL
One of the exclusive features of the GX-280(D) is the
ability to momentarily stop the tape during recording or
playback. Also convenient for editing tapes, Use when
certain portions of the program are not desired. After the
Pause Button has been depressed, it can be locked into
position by turning it to the right.
CAUTION : Pause control does not function during fast
forward or rewind operation.
AUTOMATIC STOP & SHUT-OFF
One of the exclusive features of the GX-280(D) is the
automatic stop and shut-off function of the unit. For
automatic stop (to stop reel movement at end of tape),
leave the Automatic Shut-Off Buttan at OUT position. Far
automatic shut-off (to cut off the power of the entire unit
at end of tape) depress the Automatic Shut-Off Button. If
shut-off is desired after one complete reverse cycle, affix
sensing tape (outside the tape) at desired reversing point)
and depress the Shut-Off Button. If automatic continuous
reverse is desired, apply sensing tape (outside the tape for
normal playback to reverse and inside the tape for reverse
to normal playback) at desired reversing points and leave
the Shut-Off Button at OUT position. In this case, if
Shut-Off Button is depressed, automatic shut-off will be
effected at end of one complete reverse cycle (the power of
the entire unit will be cut off).
FAST FORWARD & REWIND
To effect fast forward or rewind, depress F.FWD or RWD
Button of control pancl. Use Stop Button to stop cithcr of
these operations.
DIRECT FUNCTION CHANGE CONTROL
Your unit features a completely automatic function change
control system for easy and speedy changing of opcrating
modes. It is not necessary to depress Stop Button before
changing modes.
MONITORING
Fig. 7
For monitoring program source during recording, set
Monitor Switch to SOURCE position. If the Monitor
Switch is set to TAPE position, the recorded signals can be
monitored as the tape passes the playback head. When
headphones are used for private listening, the Switch must
be set to TAPE position, and the Speaker Switch to MUTE
position,
REMOTE CONTROL
Fig. 8
All operating functions of the GX-280(D) can be remote
controlled by using Akai Remote Control unit RC-16
optional accessory. Plug in remote control connector to the
socket provided on rear panel.

AUTOMATIC & MANUAL
REVERSE PLAYBACK
a eare Crartatatel
POSSESS SSS
OATS SS Oo
RIO ADO
tors SAIN SAS
Ps Ss LoS aN
|
I
TAPE (OUTSIDE)
Sensing
Jape
l
Sensing
Tape
Sensing
Pole
Fig. 9
For automatic reverse playback, affix about a 2 cm (1/2”)
long: piece of metallic sensing tape to the outside of the
recorded tape at desired reversing point. If continuous
reverse between two points is desired, affix another piece of
sensing tape to the inside of the recorded tape at desired
reversing point. Normally, it is recommended that the
sensing tape be affixed at both ends (outside the recorded
tape for normal to reverse playback, and inside the
recorded tape for reverse to normal playback) of the
recorded tape. As the sensing tape passes the Sensing Poles,
reverse is effected, This Akai reversing system differs from
ordinary reversing systems in that when reverse is being
effected, the motor revolutions are reversed and the Pinch
Wheel automatically separates from the Capstan , suspend-
ing reel movement momentarily until the exact tape speed
to which the recorder is set is reached. At this time, the
pinch wheel again automatically contacts the capstan and
the tape begins to travel. Thus, tape speed is always
accurately maintained and annoying noise as the tape
reverses is completely eliminated.
The GX-280(D) is also cquipped with a manual Reverse
Button for your convenience. Reverse playback can he
effected at any point by simply depressing this button.
DIN JACK
Fig. 10
The DIN Jack at the rear of the recorder is used for
inter-connecling the GX-280(D) with an external stereo
amplifier. This system enables easy recording or playback
through an external amplifier as the complex conriection or
disconnection of four separate plugs is not necessary. When
recording from an external amplifier, if the output level of
the amplifier is more than 50 mV, set the High/Low Input
Switch to HIGH. If the output level is less than 50 mV, set
to LOW.
Note: When using Din Cord connection, VU level is
controlled with the Microphone Recording Level Controls.

PLAYBACK
Please check the following prior to operation.
* As tapes which have not been used for a period of time
may have become sticky, run once before using.
* Tape is loaded properly.
Stereo Playback
Connect power cord and load a pre-recorded tape.
A. Turn on Power Switch.
B. Depress STEREO Track Selector Button
C. Depress Speed Selector Button according to the desired
speed.
. Set Monitor Switch to TAPE position,
. Depress Forward Button to begin tape playback.
. Adjust Left and Right Volume Controls.
. Adjust Tone Controls.
. To stop playback depress Stop Button.
ZaAMmMmys
Monaural Playback
Only the left channel is used for monaural playback on
Tracks 1 and 4. Substitute the following steps for steps B
and F of stereo playback procedure.
B. Depress 1-4 Track Selector Button.
F. Adjust Left Volume Control.
Only the right channel is used for monaural playback on
Tracks 3 and 2. Substitute the following steps for steps B
and F of stereo playback procedure.
B. Depress 3-2 Track Selector Button.
F. Adjust Right Volume Control.
* Your GX-280 is equipped with two speakers. However, if
a more dynamic sound is required, make connections as
shown in figure.
Fig. 12
iE]

RECORDING
Fig. 13
Please check the fullowing prior tu operation.
* Heads are demagnetized.
* Use good quality tape. New tapes give best results.
* As tapes which have not been used for a period of time
may have become sticky, run once before using.
* Tape is loaded properly.
S.R.T. SWITCH
Model GX-280(D) is equipped with an SRT Swilch. This
switch brings out the maximum response of high perfor-
mance low noise tapes and works to change the recording
equalizations according to the tape. The combination of
Akai’s GX-HEAD and the Super Range Tape has enabled
startling progress in tone quality. In other words, event-
hough the GX-280(D) provides a high frequency response
covering 24,000 Hz with standard tape, this is extended to
an amazing 26,000 Hz when Akai’s super range tape or
other make low noise tapes are used.
Stereo Recording
Connect power cord and load a Lape.
A. Turn on Power Switch.
B. Depress STEREO Track Selector Button.
C. Depress Speed Selector Button according to desired
speed,
D. With Reset Button, set Index Counter to 0000. This
Index Counter provides an easy reference for locating
positions on the tape.
E. Insert microphone plugs into Microphone Jacks.
Maintain at least two meters (7 ft.) between micro-
phones.
F. Set Monitor Switch to SOURCE position.
G. Adjust and balance microphone input level with the
Microphone Recording Level-Controls while observing
Left and Right VU Meters. Normal recording should not
exceed zero VU on either VU Meter.
H. When an optimum recording level has been determined,
depress Recording Button and Forward Button to begin
recording. Note that when recording, the recording
indicator lamp is lit.
I. To stop recording, depress Stop Button.
Note: Tone Control has no effect during recording.
Monaural Recording
For monaural recording, substitute the following stcps for
steps B, E, and G of stereo recording procedure and add
step J.
@ Only the left channel is used for monaural recording on
tracks 1 and 4,
B. Depress 1-4 Track Selector Button.
E. Insert microphone plug into Left Microphone Jack.
G. Adjust and balance microphone input level with Left
Microphone Recording Level Control while observing
Left VU Meter. Normal recording should not exceed
zero VU on VU Meter.
H. Invert reels to record on track 4.
@ Only the right channel is used for monaural recording on
tracks 3 and 2.
. Depress 3-2 Track Selector Button.
. Insert microphone plug into Right Microphone Jack.
. Adjust and balance microphone input level with Right
Microphone Recording Level Control while observing
Right VU Meter. Normal recording should not exceed
zero VU on VU Meter.
J. Invert reels to record on track 2,
QO mw

Recording from an External Amplifier
If an external amplifier or tuner amplifier is used, connect
the Tape Outputs of external amplifier to the Line Inputs
in step E of recording procedure, VU level is controlled
with the Line Recording Level Controls. Model GX-280(D)
will record any source which can be selected on the
external amplifier.
Important: If the DIN Jack is used for connecting to the
tecorder, VU level is controlled with the
Microphone Recording Level Controls.
Recording from a Turntable
To record from a stereo or monaural turntable, a crystal
pick-up or a ceramic pick-up can be connected directly to
the Line Inputs in step E of recording procedure. If a
magnetic cartridge is used, it must be connected to the Line
Inputs through a separate pre-amplifier or external ampli-
fier. VU level is controlled with the Line Recording Level
Controls.
TAPE DUBBING
When dubbing from another tape recorder, connect the
Line Outputs or External Speaker Jacks of playback
machine to the Linc Inputs instead of step E of recording
procedure. VU level is controlled with the Line Recording
Level Controls.
RecePese FIGHT
REC/pa FIGHT
PLAYBACK MACHINE
REC/pa RIGHT
RECORDING MACHINE
Fig. 16
1]

SOUND-ON-SOUND RECORDING
TRACK SELECTOR
RECORDING HEAD
TRACK SELECTOR
MONO. 1-4 MONO. 3-2
P.B. HEAD RECORDING HEAD
TRACK
Soi, Mi, Fa, Re Mi Do
err
MIC RECORD LEVEL
CONTROL
For transfer of previously recorded material from one track
to the other, accumulating as many individual recordings on
one track as is desired. Can be applied to language training,
musical compilations and various other uses.
First Recording
1.Confirm that there are no connections to the Line Input
Jacks.
2.Depress 1-4 Track Selector Button for recording on
track 1.
3.Insert microphone plug into Left Microphone Jack.
4.Depress Monitor Switch to SOURCE position.
5.Depress Record Button and Forward Button simulta-
neously to begin first recording ; i.e., Do-Re-Mi.
6.Adjust the Left Microphone Recording Level Control
while observing the Left VU Meter.
7.When the first recording is completed, rewind tape to
starting position.
Second Recording
8.Confirm that Monitor Switch is at SOURCE position
and depress Sound-On-Sound Button.
9.Depress 3-2 Track Selector Button for recording on
12]
PB. AMP.{LEFT}
=>
RIGHT
LINE RECORD
LEVEL CUNIHOL
RIGHT
MIC RECORD LEVEL
CONTROL
HEADPHONE
Fig, 17
track 3 while listening to track 1.
10.Insert microphone plug into Right Microphone Jack.
11.Increase Line Recording Level Control to approximately
maximum.
12,Connect Stereo Headphones for monitoring the first
recording on track 1.
13,Depress Record Button’ and Forward Button simulta-
neously to begin second recording ; i.e., Mi-Fa-Sol. First
recording is head through headphones.
14,Adjust Right Microphone Recording Level Control while
observing the Right VU Meter. As the second recording
Mi-Fa-Sol is made on track 3, the first recording
Do-Re-Mi is monitored in headphones. The two record-
ings will be completely merged on track 3; i.e.,
Do-Mi-Re-Fa-Mi-Sol.
15.The third and subsequent recordings are made in the
same as the second recording by alternating tracks 1-4
and 3-2. 1
16.For playback, if last recording is made on track 1-4,
depress 1-4 Track Selector Button. If last recording on
track 3-2, depress 3-2 Track Selector Button.
Note: Be Sure to keep Volume Control at minimum when
recording in order to avoid howl.

SOUND MIXING
For mixing microphone and line input signals, proceed as
follows :
1. Insert microphone plug(s) into microphone jack(s) and
connect line outputs of the external source to line input
of model GX-280(D).
2. Adjust microphone volume level with Microphone
Recording Level Controls and line input level with Line
Recording Level Controls.
Mixing can also be effected by using the DIN Jack and Line
Input connections simultaneously. For playback, operate
Track Selector Buttons according to tracks used in making
recordings,
TAPE SPLICING & EDITING
Fig. 18
Cut tape diagonally with an overlap so that the ends are
lined up (culling Lupe on diagonal eliminates detection of
splice in recording). Cover aligned ends with splicing tape.
Press firmly exerting pressure to secure ends evenly. Trim
off excess splicing tape cutting into splicing tape very
lightly as illustrated by the dotted lines in figure. This
eliminates the possibility of a sticky splice. Splicing of tape
using scissors requires skillful work. For easy and smooth
tape splicing, we recommend Akai Tape Splicer model
AS-3.
TAPE ERASING
Any signal information previously recorded on a tape will
be erased automatically as a new recording is made on the
same tape. For erasing only, thread the tape and set
machine to recording mode. No plugs should be connected
to the recordcr’s input jacks and volume controls should be
kept at minimum. Akai’s Tape Eraser model ATE-7 is
recommended for quick and complete erasure.
HEAD DEMAGNETIZING
Fig. 19
Normally the steel pole pieces which form part of the
recording and playback heads become slightly magnetized.
The effect of magnetization is that it partially erases the
tape, especially at high frequencies. Severe magnetization
which may be caused by using magnetized tools in the
vicinity of the heads, will result in noise or considerable
distortion in addition to the loss of high frequency
response. Although this model already has a built-in head
demagnetizing circuit, it is recommended that demagneti-
zation be performed periodically. This can be accomplished
by touching the heads very lightly with the prongs of the
demugnetizer and making several small circular movements
over all head surface areas as well as the head housing. Akai
Head Demagnatizer model AH-8 is highly recommended for
perfect demagnetization. ;
i3]

PLAYBACK USING MODEL GX-280D
TAPE DECK
Please check the following prior to operation.
* As tapes which have not been used for a period of time
may have become sticky, run once before using.
* Tape is loaded properly.
Model GX 280D does not include power amplifiers or
speakers. It is, therefore,.necessary to provide an external
amplifier and a pair of speakers for playback.
Connect the Line Outputs to the Tape Inputs of the
external stereo amplifier and connect two speakers to the
amplifier.
Connect power cord and load a tape.
Stereo Playback
A. Turn on Power Switch.
B. Depress STEREO Track Selector Button.
C. Depress Speed Selector Button according to desired
speed.
. Set Monitor Switch to TAPE position.
. Depress Forward Button to begin tape playback.
. Adjust Left and Right Volume Controls of the GX-280D
and Volume Controls etc. of the external stereo
amplifier.
mo
FS)
Monaural Playback
Only the left channel is used for monaural playback on
tracks 1 and 4, Connect the Left Line Output of the
GX-280D to the Left Tape Inpul or Aux Jack of the
external amplifier and connect a speaker to the Left Output
terminal of the external amplifier. Substitute the following
steps for steps B and F of the stereo procedure.
B. Depress 1-4 Track Selector Button.
F, Adjust Left Volume Control of the GX-280D and the
Left Volume Control etc, of the external amplifier.
Only the right channel is used for monaural playback on
tracks 3 and 2. Connect the Right Line Output of the
GX 280D to the Right Tape Input or Aux Jack of the
external amplifier and connect a speaker to the Right
Output terminal of the external amplifier. Substitute the
following steps for steps B and F of the stereo procedure.
B. Depress 3-2 Track Selector Button.
F. Adjust Right Volume Control of the GX-280D and
Right Volume Control etc. of the external amplifier.
FOR RECORDING WITH MODEL GX-280D,
PLEASE REFER TO PAGES 10 to 13.

TECIINICAL DATA
Track System .......
Maximum Reel Capacity .
Tape Speed .........
Wow & Flutter ......
Equalization ........
Frequency Response ....
Signal to Noise Ratio ...
Erase Ratio .........
Cross-Talk ..........
Heads: 3 scerrvses oS Ph
Motors .........005
4-track 2-channel _ stcrco/
monaural GX-Head focused-field
recording system
7" reel
7-1/2 and 3-3/4 ips (+0.5%)
Less than 0,08% RMS at 7-1/2 ips
Less than 0.12% RMS at 3-3/4 ips
Correct equalization for play-
back of tapes recorded to NAB
curve
30 to 26,000Hz (+3dB) at
7-1/2ips; 30 to 22,000 Hz
(+3 dB) at 3-3/4 ips using Akai
Super Range Tape
30 to 24,000Hz (+3dB) at
7-1/2 ips; 30 to 19,000 Hz
(43. dB) at 3-3/4ips using
standard tape
Less than 1.5% (1000 Hz “O” VU)
30 W total music power (15 W/15 W)
at 8 Q (GX-280 only)
20 W continuous power (10 W/10 W)
at 8 Q (GX-280 only)
Better than 50 dB
Better than 70 dB
Better than 70 dB (monaural)
Better than 50 dB (stereo)
100.kHz
3 Heads: 4-track stereo/monau-
ral Glass & Crystal Ferrite
recording and playback heads ;
4-track erase head
3 Motors: Outer-rotor 2-speed
motor with Servo-Control for
Fast Forward &
Rewind Time .....
Recording Capacity...
Output Jacks........
Input Jacks .........
Din Jack ...........
Integrated Circuits ...
Power Requirements ....
Power Consumption ....
Dimensions .........
direct capstan drive ; two 6-pole
eddy-current outer-rotor motors
for supply and take-up reel drive
75 seconds using a 1200 ft tape
at 50 Hz; 60 seconds using a
1200 ft tape at 60 Iz
2 hrs. stereo recording using a
1200 ft tape at 3-3/4 ips
Line (2): 1.23 V (“0” VU) /
10092;. required load im-
pedance : more than 20 k{Q2
Phone (1): 30 to 40 mvV/8 2
Speaker (2): 15 W/8 Q each
(GX-280 only)
Microphone (2): 0.8 mV/10 kQ
Line (2): 150 mV/150 kQ
0.4 V/SO mV (High), 5 mv (Low),
68 kQ
Transistors: 41 (GX-280D: 39)
Diodes : 36 (GX-280D : 32)
Power IC : 2 (GX-280 only)
Linear IC: 2
100 V to 240 V A.C., 50/60 Hz
160 W (GX-280D : 130 W)
445(W) x 465(H) x 237(D) mm
(17.8 x 18.6 x 9.5")
435(W) x 465(H) x 237(D) mm
(GX-280D)
(17.4 x 18.6 x 9.5”)
23 kg. (51 Ibs.) (GX-280D :
21 kg. (46 Ibs.)
Specifications subject to change without notice.

STANDARD ACCESSORIES
Model GX-280 Model GX-280D
7" Demonstration Tape ........... 1 7’ Empty Metallic Reel ........... 1
7" Empty Metallic Reel ........... 1 Connection Cord..............0.0. |
Sensing Tape .............0000005 I “Sensing Tapes ecatiescesatis wot es aoa bet 4c 1
Spare PUSe: olde euewes dG asacee Ieet. -“SOare Fuses os 6 ee dab ae aa ace 1 set
Operator’s Manual..............0. 1 Operator’sManual ............... 1
OPTIONAL ACCESSORIES
DUST COVER DC-250 TAPE SPLICER AS-3
DYNAMIC MICROPHONES
Uni-directional UM-101
Non-directional DM-1 3 |
REMOTE CONTROL RC-16
HEAD DEMAGNETIZER AH-8
STEREO HEADPHONES
ASE-22
ASE-20
=|
CONNECTION CORDS
D-100
DR-110
16

TAPE ERASER ATE-7
(2.
SPEAKER SYSTEMS SW-175
STEREO AMPLIFIERS AA-8500 AA-5800
a
aemearts
tt
¢
os
FM/AM Mpx Stereo Amplifier Stereo Pre-Main Amplifier 5-Way 6-Speaker System
AA-6600 AA-5500 SW-155
FM/AM Mpx Stereo Amplifier Stereo Pre-Main Amplifier 4-Way 4-Speaker System

MANUFACTURED & DISTRIBUTED BY
AKAT ELECTRIC CoO., LTD.
AKAI TRADING CO., LTD.
12-14, 2-chome, Higashi-Kojiya,
Ohta-ku, Tokyo, Japan
Price US $1.50 PRINTED IN JAPAN