Tascam M-300 Series, Operation & Maintenance Manual

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capacitors to discharge, then continue
to turn off the remaining equipment.
Turn the mixer off last.
When the system is operational, begin making
the initial control settings. We suggest starting
with all the EO controls set at 1 2 o'clock and
the AUX send controls off (fully counter­
clockwise). Set the channel input select switches
( L INE) to the appropriate position; M I C (up) or
Ll N E (down) . Assign the channels to the desired
groups using the assignment switches and PAN
controls. Remember, even if a channel is assign·
ed to only one PGM group, the PAN control
will still affect the signal. Thus the PAN should
be turned all the way to the left or right if
only one PGM group is selected.
Begin setting the input gain levels, starting with
the first channel, by turning the M I C or L I N E
gain T R I M control to the 12 o'clock position.
If the channel is assigned to a PGM group,
raise the corresponding PGM FADER to the 7-B
position. If the channel is assigned to the LEFT
and RI GHT STE REO MASTERS, raise those
FADERS to the 7-B position. These settings
approximate the unity gain position of the PGM
and STE REO MASTER section amplifiers and
allow relatively accurate VU meter readings.
Remember, this procedure is the initial gain
setting step. I n the actual rehearsal prior to the
performance, minor adjustments are usually
made to "fine tune" the various control
settings.
If the channel is processing a MIC signal, have
someone speak into the M IC. Engage the channel
"ON" switch and slowly raise the FADER. The
level will be correct if the assigned PGM or
MASTER VU meter reads ·near or at 0 and the
channel FADER is set between 7-8, the shaded
area on the fader scale. If the fader is below this
range, reduce the gain trim slightly and raise
the fader to the desi red position. If the fader
is above 8, lower the fader to the proper range,
then slowly increase the gain trim until the VU
reading is correct (at or near 0).
If the M I C signal level is too high or strong, the
channel O L (overload) LED will fire. If this
indicator is on constantly, turn the MIC TRIM
control down. If this fails to correct the over·
load condition, press the PAD switch. This
inserts a 30 dB pad into the mic circuit prior
to the first stage of gain, thus reducing the
possibility of overloading and distortion. If the
O L LED only flashes periodically, but the
channel fader is at a low position(below
6).
adjust the MIC T R I M control down until the
fader can be raised to the proper level. These
procedures are designed to provide you with the
proper amount of gain, the lowest noise and the
most headroom possible.
Line level signals such as those generated by a
synthesizer, as in our example, may be set in
a similar fashion as the M I CS. Merely select
LINE as the source and adjust the L I N E TRIM
control and fader for the desired level . Unlike
MIC signals, instruments which generate l ine
levels usually provide an output level control.
This external control must be properly adjusted
to prevent overload of the L I N E I Nput.
When all the various channel levels have been set,
and the channels assigned, the final PGM and
STE REO levels can be determined. I n our
example, we have assigned several signals to the
four PGM GROUPS and others directly to the
LEFT and R IGHT STE R EO MASTERS. The
obvious questions arising from these actions
are: Why use the PGM G ROUPS? and, How is a
PGM GROUP signal mixed to the STE R EO
MASTERS?
First, let's look at the assignments. We've
assigned different instruments or voices which
perform similar musical tasks to the same groups.
As an example, the two background vocal
mics are assigned to PGM 1 . This allows the
operator to control the final level of both m ics
with only one fader. I n other instances, such
as the lead or main vocal mic, the signal is sent
directly to the STE R EO MASTERS, bypassing
the PGM G R OUPS. This allows the signal to
be varied in the final mix without disturbing
any other signal. This method of mixing reduces
the complexity of the mix while still allowing
full creative control.
Adding the PGM GR OUP signals to the STE R EO
mix is relatively simple. Above each G ROUP
FADER there are two identical, yet separate,
MONITOR sections. Each section is numbered,
1 -8, and contains an input select switch (TAPE
RTN), a LEVEL control, a PAN control, and an
ON switch. On the M-312 and M-320 models,
there is an additional control not found on the
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