Teac A-6010GSL - Record Amplifier Performance; Bias Trap Adjustment; Bias Adjustment

23
RECORD AMPLIFIER PERFORMANCE
IMPORTANT: Before making any adjustments on the record amplifier,
be sure that all tests in the MECHANICAL HEAD ALIGNMENT, PLAYBACK
and MONITOR PERFORMANCE sections have been accomplished and that
all adjustments are correct. Optimum recording performance (Bias
levels, recording levels and frequency response) depends upon tape
characteristics. The TEAC A-6010GSL is factory preferred set for
Scotch type 203 tape. Service data is based upon the use of
Scotch 203 or a close equivalent tape.
BIAS TRAP ADJUSTMENT
NOTE: The bias trap tank circuit keeps the bias signal from reach~
ing the record and monitor amplifier and under normal "no signal"
conditions, voltage should not be present at the LINE OUT jacks.
NOTE: See figure for the location of these adjustments.
1.
2.
3.
Thread a blank tape or block
tension arm in ON position.
Place the MODE L:R switches up.
Place the BIAS switch to HIGH
and place the unit in the record
mode. Place the EQ/LEVEL switch
in the HIGH position.
Connect a VIVM to the junction
of L-103/203, R-145/245 and ad-
just L-103/203 for a min. reading.
Connect a VIVM to the LINE OUT
jack. Adjust L-101/201 for a min.
reading on the VIVM.
L-CHANNEL R-CHANNEL
THE PARTIAL DIAGRAM OF
REC/PB AMPL. PC BOARD
Fig. 7-10 Traps Check Point
M0849
BIAS ADJUSTMENT - Adjustments Are Accessible From The Rear Panel.
NOTE: These adjustments are only made at 7-1/2ips tape speed.
The bias oscillator frequency is 100 kHz (+10 kHz).
HIGH bias position
1.
2
3.
4.
Thread Scotch 203 recording test tape onto the unit.
.
Place
the
BIAS
EQ/LEVEL
switch
to
HIGH,
the
MONITOR
switch
to
TAPE.
Place the unit in the record mode.
With the level meter connected at LINE OUT jacks, adjust capacitors
VC-102/202 for a peak reading in each channel.
Then retard the capacitors clockwise until a decrease of 0.5 dB is
indicated.
NORMAL bias position
5.
6.
Thread a Scotch 150 recording test tape onto the unit.
Change the BIAS switch to NORMAL and place the unit in the record
mode, Adjust as above with VC-101/201.
7-7