Akai 1700 User manual

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AKAI TAPE
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IASTE OF CONTENTS
I spEctFtcAnoNs.. .....'.....'......
I
I HOW TO A.TEASUREDESIGNATEDVALUES
OF
SPEC|F|CAT|ONS..,...... ..............' 2
I tocafloNoFcoNlRor.s
..... . ..........................,
3
IV DrsAssEMrLy
oFtApETRANSPoRTuNtTs
ANDAMPL|F|ERS......... ......... ... ,l
v TRANSPORI
MECHAN|SL ............... 6
IJ ADJUSTMENT
OF
TAPETRANSPORT
UNIT
................."..
9
II ADJUSTMENT
oF
al4pr|FrER
....................................'10
rlf r,{A|NTENANCE
pRocEDURES.. ............. .............It
X( Lrsl
or REPLACEI ENT
pARTs....................................12
X ExpLoDEDvtEw
oF coMpoNENt
p^RTs..................,.1,4
xI TROU3LESHOOTTNG
CHART
................,..............,.21
n scHEfiATtCDTAGRAM
.,.....,............,..'.................25
xI CoNNECTINGDfAGRAl.r
...................-..--.-.-.-......-.26

SPECIFICATIONS
MODEL
NUMBER
wtrGHT (NET
IN CARTON)
DIMENSIONS
POWERRE-
qUIREMENTS
POWERCON.
SUMPTION
RECORDINC
Akai Modcl 1700, portablc 4-track
st.rco tape rccorder.
33lbs (15 kg)without acccssorics.
t3-t6' lH)x 13-%' (w) x 9' (Dl case
A.C.100,ll0,120,200,220or240volts
interchang€abl€.5060cycles.
80VA.
Inline 4 t.ack st€reoand 4-tfack mon-
Inlin€ 4.tiack stefeo,monaural play-
Thrce speeds
cmland l-%" (a.is cmJpersecond.
(15"
p€r s€cond with an optional accessory
capstanand pinch whe€I.)
SYSTEM:
PLAYBACK
SYSTEM:
TAPESPEED :
.I'APE
SPEED
DEVIATION :
WOWAND
FLUTTER :
TIME
FRDqUENCY
RDSPONStr
DISTORT'ION
SIGNAL-TO-
NOISE RATIO
CROSSTALK
CHANNEL
SEPARATION
Less than + 3 pef cent at all tape
Lessthan0.2
% at 7-t6ips.R.M.S.
Lessthan0.3
% at 3-7aips.R.M.S.
Lessthan0.45
% at l-16ips.R.M.S.
FAST FORWARD
AND REWIND 150secondsfof 1,200ft. tapc at 50
cy-
cles
and 120
s€condsat 60cyclcs.
40to 18,000cps.at 7-%;ps;
.L3db.80 to 12,000cps.at 7-l, ipsj
+ 3 db.80
to 10,000cps.
at 3-3la;ps;
+ 4db. 80at 4,000cps. at l-7sips.
Within4%at l,000cps,oVU
ltotal
40db belowrccordedlev€lsignal at all
Within 55db betweeneachtrach.
Betterthan
80db at l,000cps
+3 VU.
POWJ]R
INPU'I'
LDVELS:
POWDR
OUTPUT:
Microphone ir)put lcvcl
-55 db (VR.
max.jat l,000cps.
Phonoand radio input levcl
40db (VR.
max.)atl,000cps.
Pre-Amplifier output, 0.7V at 1,000
cps,impedanc€
morethan l00K ohms.
Mainoutput,34dbm.
up
(in
600ohmt.
More than
50MEC ohns.
Morethan
orem;nuteatA.C. 1,000V.
With headphor€ during reco.ding.
Condenser start;ng induction two-
l/l00HP. Power
factor,70
pe.cent.
2,900
to I,450
r.p.m.at 50
cps,
3,480to 1,740
r.p.m. at 60cps.
lnline +tf ack
stereo/monau.alrecord-
play h€ad;
Impedance..
.3,500
ohms + l0 % zt
I,000
cps.
4-trackerasehead
;
Imp€danc€.
..4,000ohms
+15% at 90
Round dynamic micropho.e
Impedance...50,000ohms
S€Dsit;vity... 55db.
f.€quency R€rpoDse...70
ro 15,000
Two 5'x7' dynahic speakers.
Imp€dance...8
ohms
AllowableIDput...6
warts
Frequency R€sponse...8oro 12,000
cps,
:!l0db.
I2AT7
x2, 6BM8x2.
l50Dx2
Up to 7' r€el
INSULATION
RESISTANCE
INSULATION
YI[,LD
STRENGTH
MONITORINC
SYSTEM
MOTOR
HEADS
MICROPHONE
USED:
SPEAKOR
INCLUDED:
TUBESUSED :
SILICON
DIODEUSED:
REELS
USED :
RECORDING
LEVEL
INDICATOR : Horizontal,
A-model
VU m€te..

1I IIOW
TO NIICNSURE
DESIGNATED
VALUES
OF
SPECIFICATIONS
TAI'I] SPDtrD
DEVIATION
:
\{OW AND
FLUTTER
:
Reco.d the l,000cps. sine curve of
the tap€ speedat rating sp€eds
with
a standa.d sound recorder (AMPEX
351A, for instance)
which is little af-
fccted by lhe tape sPecd deviation
tlrroughout the whole i€ngth of the
tape. Put th;s standard taPe on th€
tapc recorder unde. test for playing
back, and nreasure its outPut bY a
couDte., then codvert thc value into
rating power frequeDcy to cvaluate
the tape speeddcviatior.
Fo. a rough measurement,the taPe
spe€ddeviation can alsobe measured
with a testing tape for speedby astop
Playback thc 3,000cpssianda.d tape
that guarante€s
wo\dand flutter with-
h 0.07
p€r cent,aid read the effect;ve
valuc otrwow mere.
Since
the sedsibility of wow and flut-
tcr frequency bclow 2cps and above
5cps.d.ops,the frequency over 5cps.
is put to 3db/OCT circuit,
and th€
frequency bclow 2.ps. is put to 6db/
OCT circuit for adjustment This ad-
justed value is called auditory com-
Connccr to thc input tcdninal of the
rcco.dcr, .ccord a sine curve swecp
f.equency at 100cps -10 db. from
Audio frequency Oscillator.
Adjusl toDe volume to flat, playback
the tapeby .onnectidg VTVM tosp€-
aL€rout put then read the frequency
response
to adjusl a maximum devia'
}.RLqUI]NCY
RESPONSE:
(OVI]RALL
I'REqUENCY
RESPONSE)
TOTAL HARMONIC
DISTORTION
FACTOR: Provide the input terminal ol the
,ecord.r with 1.000.ps.
':nF ,urvF
signalsand .ecord thesesignalson a
recording tape at the zerolevelonthe
recorder's
VU mete.
Then playback the siSnals
under the
no.mal recording condit;on to meas-
u.c the distortion factor by an oscil
lator. Remove the recording tapc
from the recorder,
then read the noisc
lcvelon theoscjllator
to 8ct therequ;r-
€d dhtortion factor by the following
formula:
d0:d-dl d2
d0..required
d...overall distortion factor
dl...noise
l€vel
d2...disto.tion
factorof theoscilla-
to. uscd
SICNAL TO
NOISE: Playback the sinecurve, 250cPS.
tape
rccorded on a standard recorder on
th€ reco.derto measur€
the voltag€
Removc the taPe, then measure the
noisc level under the samecondition
Calculate the ratio between the two
in d€cibel.
OUTPUT: I'layback on the recorder
thc 1,000cps.
sine curvc tape which was record€d
at the zero VU level on a standard
recorder. T€rDinatc the test recorder
with €ight ohms.
Square the voltag€ rcading, then di
vide the figure by eight ohms to get
thc r.m.s.
Powcroutput.
CROSS TALK: Record 1,000cps.
signal at +3VU on
the third tack, then playback this
signalthrough a l,000cps. Band Pass
Filter.
Compare the output of tracks I and 3
in decibels.
2-

f
ILOCATIONOFCONTROLS
@
@
@
(D
(D
o
@
@
o
o
o
0
@
@
o
o
@
o
@
o
@
@
@
(D
(D
@
@
Supply rccl shaft
Cyclc convcrsionswitch
Capstanstorage
post
Tape guide
trras€
head
Right channelvolumc control
Right channel tonc control
Left channcl microphone input jack
Right channelmicrophone input jack
Left channelvolumc cont.ol
Left channel tonecontrol
Speed
changeswitch
Take-up reelshaft
Capstan
shaft
Pinch wheel
Automatic stoplever
Record/Play switch
Rewind/FasFforward switch
Record safetybutton
Automatic stopswitch
Stereoheadphonejack
VU h€ter conv€rsionswitch
Track s€lectorswitch
Cycle conversionsw;tch
Hum adjust (right)
Speakeroutput jack (righr)
Speakeroutput jack llert)
Voltage sele.torswitch
Preampoutput jack (right)
Preamp output jack {left)
Phono/Radio input jack (l€ft
Hun adjust (left)
Phono/Radio input jack (rish0
3

I\I DISASSEMBLY OFTAPETRANSPORT
UNITS
& AMPLIFIERS
ll l-oo!',,rh. ltl:.1.\I\ lN(; SUIlll\f irlof I'INCIt R()L-
LI{l , ,lt-'.. ,\vl,v ," !i
ih. l'IN(ill lt()l.l.l lt llil.
13)
L,{iJ.! thcS(lltli\\'S nrxrl.(l 1,,,))
r.rir(j
t{ll
i,r
('(1,.r
ro
r.!!^! l)1'lCK
l).\\l.ll. tl)1.
12 l.(.,,,,tr| tlx.I)llUK C()\ l R()I-ti\( )lls
ialrndiblby
io,!c,,i,ig d,cif ritx;fing s.raL. u';i)g r I)liillips
h.adcd
o
99
r.t
I
('11
l.oosci
(h(i
S(iltl:,\\'S,,)rrk.d
f,or) i.t r,)
ktr.
I

(5) Loosenthe SCREWS narked from {a)
to (d).
Lifl TAPE DECK and
cabinet (B). AMI'LIFIliR (Dr tr"m ,he
(7) Disconnectthe PINS of speako marked {a)
and (d), the
PLUGS or motor marked (€)
and (f) and the PINS of
headmarked {B)and {j).
(8) Loosenthe RETAINING SCRDWSof dcck frame
mark€d
from(al toid)
(9) SEPA'AIC
TAPE DtrCK (M) frOM AMPLIFIER (A).

YTRANSPORTMECHANISM
Driving of Capstan
Fjgure l. {Aj Motor
(B) Driving Belt (flatbelt)
(C) Capstan
(D) FlYwheel
High-speedrotation of Mot / (A) isreduced by D/trire'
Br, (B) and transmitted to Capstan (C),
which isconnected
to Flywheel with ample inertia and €nablesrated rotaiion
by absorbingmino. rotation distortion ofDotor itself.
CapstanRotation 606r.p.m.
at 7-%'(l9cn)pe. sec.
303r.p.m.at 3-%'(9.5 cm) per sec.
l5l.5r.p.m, at l-16'(4.7s cmlper sec.
Motor Rotation 2,900to 1,450r.p.m.at 50cps.
3,480to 1,74{r.p.m.at 60cps.
Fig. I
Driving of Pinch Roller
Puttapebetweenrotatingcapstanand pinchroller
and
pushpinch roueragainst
capstan,
thiswill transport
thc
tapeat rat€dspe€d. Th€ appropriatepressureof pinch
roller is betweenI,000to I,150
gramsat the tape sp€ed
of 7-%' (19cm) pers€cond.
R€coding and Play Back
TuJ[ rheRECORD,PLArB,4Cf knob
(A)to "PLAY"
position, and pinch roller pressesagainstcapstanto move
tape at the rated sp€ed. At the sametime, Idlel (B)
moves
between Motor &tshitag ICI znd t}:'e Tahe-Ut Reel Spindle
lD) b rr^ns'lr.it the motol /rldtro, to {D) so that th€ tape is
moved and wound on the take-up re€I.
The Tak€-Up ReelSpindle Baseis made up of two plas-
tic rollers(l and 2lwith a clutch felt in betw€€n.The ldler
is rot^titg the plastic mUel (2)under. Therefore, the tape-
winding friction is adjust€d by the slipping of the felt to
enabl€rated winding of the tap€.
on the other ha d, the S*pfb Reel Sbtndle IHI h^s a
Blake lo e/ lEl hwg on the Plastic Roll€r {4)under which
provides
app.opriate back tensionby the .lutch fet slipp-
ing to the rotation ofthe Pull€y (3)above.
To prevent accidental er^sure, the Record lnterloch But-
to, (F) mut be depressed
before the RECORD, PLAY-
BACK knob can be moved to the "REC" position. The
Safet! dnice lclls depressedto ente. the record mode
(See
Fisures2and 3)
ffi
\ir
Slipping Rotation
Fig. 2
-6-

f
FAST-FORWARD MECIIANISM
TurD lie aASZ FWD-REWIND *no, (A) to "FAST
FWD" position,and ll's ca- (B) undcr lhc knob pushes
up
the Lerer (C). The l.tler (D) moves into the spacc
bctween
thePlast c RouerlF) above the Take-Up Reel Spindle and
the uppe. part of th. rotating motor drive bushing to
transm;t the motor rotat;on to thetakc-up reel spindle. At
the same tihe, Brale RoUerc
lH) and (I) cone otr the reel
sp;ndleto free
lr, Srrrl! ReelSti dlelcl,rheteby allowiDT
fastwindnrg ofthe tapc onto thc iakc-up rcel.
(Sec
ligures 4 and 5)
FreeRolarion Fl;gh-SpeedRotation
Fig.5
Fig.4 o
REWIND MECHANISM
"f
utntheFASTFWD-REtl/N, izo, (A)ro
"REWIND"
position,and thecamlB)u^det$e k\ob ptshes
theLeuer
lC)up. The
ldlerlDl noves intothc space
betwecntheup-
per part of the rcIatingMotar dtue bushing
lE) andthe
InternedatePulle,lF) to hansmit
thehigh-speed
rotation
of themotorthroughtheinterm€diate
pulleyto tr? Srrrll
Reet
Spindte
lC).At the
sahetime,Brale
Roll€ls
(H)
and
(I)
comeofl the re€lspindleb treethe
take-atleelspindte
lJl,
ther€byrewindingthe tapeinto rhesupplyreel
ar a fast
(See
F;surcs
6 and7)
High'SpeedRotation
Fig. 7
'J YO
o
(a)
sToP o o
(b)FAST-FORWARD o
(.) REWIND o o
Id) RECORDING o o
STOP
CONTROL
Push ihc stop lever to "STOP" positlon, Bruke Ro els
{A)and 1B)
depres reelspindlesto stop.otation of the reel
sp;ndles.
As thc brake rubb€r depfessesthe plastic rolleG under
the .eel spindles,no triction works on the tape its€lf.
Supply R*l Spindle R*ind ldle$heel Take-up Reel Spindle
NOTES : x -marksindicates
"open" and
O-ma.ks "engaged"
fig. 8
7
('

RDCORD/PLAYBACKCIIANGING MECHANISM
By turning the RLCORD/PLAYBACK KNOB (N)to the recordingposition,thr LEVIiR 1a)pulls
the RECORDING
LEVER (bi and (c), as
;llushatedin dotted l;nc,
then the RECORD/PLAYBACK CHANGD SWITCH (SWl)turns
to .ecording position.
If the LIVER (c)do.s not turn
Then must adjust
the LI.VIR
propc.ly. SWI docs not operatc prope.ly so may occu. the abnormal oscillation and
(cl
to properposition
by loos;ngthc SCREW lcll.
.
r il.', - ,z--\
Itz__\,/..r',
'l-a1'1';': ,
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