Toa A-912MK2 - Manual (Page 7)

7
[Front]
1. Power switch [ ON / OFF]
Power is switched on and off with each
depression of this switch.
2. Power indicator [POWER] (Green)
Lights green when the Power switch (1) is
switched on.
3. Peak indicator [PEAK] (Red)
Lights red if input signals approach clipping level.
If steady lit, turn down the corresponding Input
volume control until the indicator flashes only
intermittently.
4. Normal indicator [NORMAL] (Yellow)
Lights yellow when the output sound volume is
appropriate.
5. Signal Indicator [SIGNAL] (Green)
Lights green when sound is output from the
speaker output terminals.
6. Protection indicator [PROTECT]
Lights red if the built-in protection circuit works
due to excessive input signal level.
This indicator remains lit for about 5 seconds
after the power has been switched on.
7. Input volume controls [INPUT 1 — 8]
Adjust the input volume of each input channel.
8. Bass control [BASS]
Turn the control knob clockwise to increase the
bass level and counterclockwise to decrease it.
Bass level is flat at the center position.
9. Treble control [TREBLE]
Turn the control knob clockwise to increase the
treble level and counterclockwise to decrease it.
Treble level is flat at the center position.
10. Tone defeat switch [TONE DEFEAT ON/OFF]
Bass and treble controls are enabled when this
switch is set to the OFF position. Setting this
switch to the ON position disables the controls,
causing the tones to be flat.
11. Low-cut switch [LOW CUT ON/OFF]
Set this switch to the ON position to cut off
unnecessary low frequencies.
12. Master volume control [MASTER]
Adjusts overall gain of all input channels.
[Rear]
13. AC outlet (unswitched)
Provides AC power to auxiliary equipment with
power consumption of less than 500 W.
14. AC power cord
Connect this cord to an AC wall outlet.
15. Impedance selector switch [DIRECT]
Placing the switch in the "DIRECT" position
enables only unbalanced low-impedance
speaker connection. Placing it in another position
enables transformer-balanced 25 V, 70 V, or low-
impedance speaker connection. For the use of
this switch, refer to p. 9, "Speaker Connections."
16. Speaker output terminals
Connect speaker cables to these terminals.
17. Remote volume control terminal [REMT VOL]
Connecting a 10 kΩ linear taper potentiometer to
this terminal allows remote control of the Master
volume control.
18. Mute terminals [MUTE 1, MUTE 2, GND]
Activates mute control only to the modules
having mute function.
Short-circuiting between MUTE 1 or MUTE 2 and
GND terminals mutes the modules set for "mute
receive" function activated on MUTE 1 or MUTE
2 bus, respectively. For more information and
connection, refer to p. 11, "Mute Control
Connection."
19. Module input ports
Accept 900 series plug-in modules. For the
selection of the most appropriate modules, refer
to Plug-in Module Instruction manual.
20. Auxiliary output jack [AUX OUT]
1 V, 10 kΩ, unbalanced, RCA jack.
Connect to the booster amplifier or a recorder
with input impedance of 10 kΩ or more.
21. Power amplifier input jack (PWR AMP IN)
1 V, 10 kΩ, unbalanced, RCA jack.
Inserting a RCA plug into this jack separates the
internal power amplifier section from the
preamplifier section. As a normal use, a signal
processing device such as a limiter or equalizer
is inserted between the Preamplifier output (22)
and the Power amplifier input.
22. Preamplifier output jack [PRE OUT]
1 V, 600 Ω, unbalanced, RCA jack.
For a normal use of this output, refer to item (21)
above.
23. Bridging input/output jack [BRG IN/OUT]
100 mV, 3.3 kΩ, unbalanced, RCA jack.
This jack is used as a mixing bus.
Connecting this jack to the similar terminal of
another amplifier achieves mixing (expansion of
input sources). The signals appearing at the jack
are independent of Master volume control, and
Bass and Treble controls, so that the jack can be
used as recording output.