NAD 602 - Trouble Shooting Guide

9. PEAKING CIRCUIT TYPE I TAPE (NORMAL)
Leave the connections of the VIVM’s as under 7.
Adjust audio generator to 14kHz while maintaining the same
output level. Record and play back the 14kHz tone and adjust
R641(L) and R642(R) to the same level as the 400Hz signal.
Tolerance: +/-1dB
WARNING: If the R/P head is worn, the tape may not have
adequate
contact
with
the
head,
resulting
in
severe
drop
outs.
A
worn
head
will
make
this
adjustment
very
difficult
or
impossible. DO NOT try to adjust the worn R/P head. Leave
R641
(L)
and
R642(R)
in
the
factory
preset
condition,
or
if
they
have
already
been
adjusted,
re-adjust
them
to
their
approxi-
mate midposition.
ALIGNMENT COMPONENTS LAYOUT
Fig. AFOR ADJUSTING TAPE SPEED
CASSETTE MECHA.
ADJUST THE SEMI—VARIABLE
RESISTOR (USE SMALL TYPE
MINUS SCREW DRIVER)
Fig. C FOR MAIN PCB
P704A
P7Q5A sos
BIAS ADJUST R679 REBE REB4
O RIGHT CH.
(TYPE 4) (TYPE 2) (TYPE 1)
O
O O Eres PEAKING P301
ADJUST 3
(LEFT CH.) ADJUST
641 (R. CH.) OUTPUT NpuT
P502 pecs P5O1 6104
@ KX Oo Oe _)
P701A P702A — P703A Js06 -J508 wf 645 64
So ae i i a
, : a7o1 2] | .. BEY 649 65
< Z 98 Ord =
: 5 oe
:
5 hy O
N
: te REC
( 4 \LEVEL 207
ceate cece (R. CH.) :
fo 2
7
nee
R601
;
js:
m
: Q713 32 e i I
SUSE) ee 2) TYPE 1) soe
LEFT
CH
S
C)
P.B.
{EVEL
P.B.
LEVEL
: .
Te
TRAP
P202A
R233
R234
20
| [| | | p.p. EQR2l’ e
10. FREQUENCY RESPONSE TYPE II TAPE (CrO2)
Insert a type II tape. Adjust audio generator to 400Hz and
6.3kHz and repeat procedure described in step 8 using R665(L)
and R666(R) to adjust both channel simultaneously. After
400Hz and 6.3kHz are adjusted properly, set audio generator
to 14kHz and repeat same procedure as described in step 9
while adjusting R645 (L) and R646(R) to obtain correct reading.
11. FREQUENCY RESPONSE TYPE IV TAPE (METAL)
Insert a type IV tape. Repeat procedure as in step 8 while
adjusting R669 (L) and R670 (R) for correct 6.3kHz level in
both channels. Set audio generator to 14kHz and repeat
procedure as in step 9 while adjusting R649 (L) and R650 (R)
for correct 14kHz record level.
Fig. B FOR ADJUSTING AZIMUTH
AZIMUTH
SCREW
R/P HEAD FRONT VIEW
R602
REC LEVEL (L. CH.)
TRAP
TRAP
a
(R)
(L)
ce
-
L604
L603
DOLBY
SW.
OUTPUT
LEVEL
UT (PLAYTRIM)
TROUBLE SHOOTING GUIDE
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