Teac TASCAM 32 - Meter Cal

2) Reproduce Calibration:
(DO NOT ATTEMPT TO CALIBRATE WITH
DBX ENGAGED!)
When
we’re
sure
the
reproduce
and
record
head
are
properly
aligned,
we
can
move
on
to
the
electronic
adjustments.
The
first
step
here
is
to
actually
check
your
meter
calibration.
To
open
the
bottom
panel,
remove
the
8
binding
screws.
Rotate
OUTPUT
knob
on
the
front
panel
to
the
position
“7”.
Connect
the
VTVM
to
the
output
terminal
of
left
channel.
Turn
the
machine
ON,
and
thread
the
15
ips
alignment
tape.
Play
the
‘operating
level’
portion
(a
voice
on
the
tape
identifies
each
section
at
the
beginning).
Switch
the
OUTPUT
SELECT
on
the
32
to
REPRO.
Adjust
the
playback
or
‘‘reproduce’’
level
with
trim
pot
#1
R120,
2k
ohms
(REPRO
CAL),
until
the
VTVM
reads
-10
dB
(0.3
V).
Switch
the
OUTPUT
SELECT
to
SYNC.
Adjust
the
reproduce
level
with
trim
pot
#2
R122,
2k
ohms
(SYNC
CAL),
until
the
meter
reads
-10dB
(0.3V).
Now
read
the
meter
on
the
front
panel
of
the
32.
It
should
read
“0
VU”.
If
it
does
not,
adjusting
trim
pot
#3
R141
50k
ohms
(METER
CAL)
will
allow
you
to
set
the
meter
on
the
32.
You
adjust
the
32
meter
to
read
“0
VU”,
not
-10,
the
reading
on
the
VTVM.
The
meter
will
read
O
at
any
voltage
you
set
it
for,
the
correct
one
is
0.316
Volt.
This
is
the
right
setting
for the
32.
You
read
-10
dB
(0.3
V)
on
the
VTVM
and
adjust
the
32
meters
to
read
O
VU
at
this
level.
Channel
R_
still
remains
to
be
checked
and
adjusted,
but
as
you
can
see,
the
adjustments
are
the
same
as
for
channel
L.
In
brief:
41
R140
. Play the tape ‘‘operating level’
. Read the VTVM for head 3, REPRO.
. Adjust for -10 dB (0.3 V) reading with trim
pot #1.
. Switch to SYNC on OUTPUT SELECT.
. Read the VTVM. Adjust trim pot # 2.
. Read the meter on the 32 — it must readO VU.
. Adjust the meter trim pot #3 R141,50k ohms
METER CAL.
Wn
NO O1
One more word of encouragement. The circuits
in the 32 are very stable. Most of the time you
will make a reading and not have to adjust
anything. When something does go wrong, you
will be able to fix it very quickly, and get back
to recording.
In summary, with the VTVM and test tape, you
have adjusted the reproduce level on the 32 to
the test tape. But your reproduce reference is
not yet complete. You have only ‘“zeroed’’ one
point ona line of frequency response. To establish
the rest of the line, you must measure and adjust
one more frequency.
Advance the alignment tape for 15 ips to the
section that is recorded at 16 kHz and adjust the
trim pot marked REPRO EQ #4, R108, 10k
ohms — switch to SYNC on the OUTPUT
SELECT, and adjust trim pot #5, R110, 20k
ohms SYNC EQ.
The reading for both positions should be 0 VU
on the 32 meters. Since you have checked and
adjusted the reproduce meter circuit, you now
can use the meters on the 32 for the test readings.
ns Ne hits tar
ee Go0u §
Ran a ener TM
#3
#2.
#1
#5
tA
R141
R122
R120
R111
R110
R109
R108