Toa W-906A Operating Instructions Manual Download Page 9

Compressor

If the COMPRESSOR CONTROL switch is set to
OFF, it bypasses the compressor circuit. Turn it
clockwise to activate the compressor and to adjust
the limiting level. Since turing it fully clockwise far
too much limits the output level, set the switch at a
maximum point that does not cause the peak
indicator to light up.

Adjusting release time

Compressor release time is set at 2 seconds on the
amplifier supplied from the factory. Adjust the
release time, if necessary, by means of the release
time controls at the rear of the amplifier.

Output Fuse

Each amplifier has an output fuse to protect the amplifier from short-circuiting at the output or overloading.
Check the fuse when speakers connected do not sound even if the meter deflects normally. If the fuse blew,
replace with the same type fuse after confirming the following points.

Step 1.

Speaker cables are not short-circuited or the load does not exceed the rating specified.

Step 2.

Wiring is correctly done at the output terminal board.

7. HOW TO USE VOLUME CONTROL COVER

Step 1.

After adjusting the input volume control, remove its knob.

Step 2.

Attach the supplied volume control cover to the chassis in place of the knob.

Note:

The unit comes with 3 volume control covers as standard accessories. Ask for the optional one model
YA-910 as necessary.

9

Output

Input

Clip

OFF

HALF

MAX

COMPRESSOR
          CONTROL

Rated

1/2

MIN

MAX

Release time control

VR303

VR302

CN302

VR301

Equalizer printed 
circuit board

2

1

Volume control cover YA-910

Input volume control cover knob

Summary of Contents for W-906A

Page 1: ...2 12 6 0 6 12 900 SERIES WALL AMPLIFIER POWER PEAK Please follow the instructions in this manual to obtain the optimum results from this unit We also recommend that you keep this manual handy for future reference 1 GENERAL DESCRIPTION 2 2 FEATURES 2 3 NOMENCLATURE AND FUNCTIONS Front 3 Front viewed with the front cover removed 4 4 INSTALLATION AND CONNECTION 5 5 SERVICING 8 6 OPERATION 8 7 HOW TO ...

Page 2: ...of the modules H 21 H 22 and X 21 permits the input signal level to be controlled remotely by means of an external potentiometer The W 906A and W 912A have a built in one octave graphic equalizer with 9 bands to tailor sound system frequency response to room acoustics reducing feed back tendencies and improving intelligibility A built in compressor circuit is provided to protect the output level f...

Page 3: ...dicator Comes on when power is switched on 11 Peak indicator Comes on when the output signal reaches the rated output power level 12 Output fuse Prevents excessive current flow W 906A 250 V 6 A W 912A 250 V 10 A 13 AC fuse Prevents excessive current flow W 906A 250 V 3 A W 912A 250 V 5 A 14 Blank panel user s space The space of 103 w x 63 h x 95 d mm is provided An optional expanding kit may be lo...

Page 4: ... independent of the all CONTROLS except INPUT VOLUME CONTROLS so that the terminal can also be used as recording output The input impedances of the equipment to be connected here should be more than 10 kΩ 23 Mute terminal With modules employing muting function which are optionally available the input signals fed to the modules are muted by short circuiting at this terminal 24 Cord clamp Clamps off...

Page 5: ... them in a junction box Step 4 Attaching the junction box to the back box The BX 9F differs from the BX 9S in the way to attach the junction box to the back box Step 5 Connecting the speaker cable Connect the speaker cable to the speaker terminals on the junction box Amplifier output impedance may be selected at the output terminals on the front panel 5 From indoor wiring Junction Box BLACK GREEN ...

Page 6: ...se characteristics may be altered In TRANS OUTPUT cut off unnecessary low frequency to obtain the best acoustic condition When connecting speakers to the 4 Ω output UNBALANCED DIRECT OUTPUT connect as illustrated below 6 M4 x 10 mm Screw 3 pcs INPUT 1 POWER ON 250V 3A 250V 6A OFF OFF MAX INPUT 2 INPUT 3 AC FUSE OFF ON LOW PASS OFF ON HIGH PASS OUT 63 125 250 500 1k 2k 4k 8k 16k 63 125 250 500 1k 2...

Page 7: ...lter and gain control H 03 Unbalanced high impedance auxiliary preamp module with presettable gain control X 01 X 11 X 21 Balanced 10 kΩ bridging transformer module B 01 B 11 Balanced 600 Ω line matching transformer module L 01 Balanced paging input module with presettable gain control and MUTE Delay I 01 Balanced 600 Ω line output module with presettable gain control T 01 Equalized mag phono prea...

Page 8: ... operation Adjustment of Volume Adjust the individual input and master volume controls to obtain appropriate output level When the peak indicator remains lit reduce the sound volume to turn it off If the system is operated with the peak indicator lighting it downgrades sound quality Adjusting graphic equalizer The one octave graphic equalizer tailors sound system frequency response to room acousti...

Page 9: ...loading Check the fuse when speakers connected do not sound even if the meter deflects normally If the fuse blew replace with the same type fuse after confirming the following points Step 1 Speaker cables are not short circuited or the load does not exceed the rating specified Step 2 Wiring is correctly done at the output terminal board 7 HOW TO USE VOLUME CONTROL COVER Step 1 After adjusting the ...

Page 10: ...er off Thermostat 105 C OT PT Power Amp COMP EQ Low cut 60Hz 6dB Oct Power Indicator Output Fuse Peak Indicator Relay Relay Master Volume Control Speaker Output Terminal Balanced Transformer Output 8Ω 25V 70V Unbalanced Direct Output 4Ω Protecting Circuit Output Muting DC Drift AC Fuse Power Switch 250V 1A 24V DC 24V DC 1 5 6 Module Input Ports 20dB V 100mV 10kΩ Vcc Vcc AC 120V 60Hz In on off on o...

Page 11: ...ds Distortion Less than 1 9 Band ISO One octave graphic equalizer Center frequencies 63 125 250 500 1000 2000 4000 8000 16000 Hz Equalization range 12 dB High pass filter 180 Hz 12 dB octave Low pass filter 7 kHz 12 dB octave 6 Input gain controls 1 Master gain control 1 Compression level control 9 Equalizer controls 1 Power ON OFF switch 1 Equalizer ON OFF switch 1 High pass filter ON OFF switch ...

Page 12: ...me control cover black YA 910 Optional products Volume control cover 3 Key for door 2 Lift off hinge receptacle 2 Machine screw M4 x 10 5 Machine screw M3 x 6 6 Machine screw M3 x 10 4 Flange nut 4 Tapping screw 3 x 8 4 Inch screw 4 Indication label 1 Instruction manual W 906A 912A 1 Instruction manual New 900 series modules 1 ...

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