Toa WA-641 Instruction Manual

MEETING AMPLIFIER
Operating Instruction Manual
WA-641
WA-641C
For wireless applications, use the WTU-77 tuner module.
Contents
Features
Important
Each Part Names And Functions
Po er Source
Mounting The Wireless Tuner Module
Operating The Wireless Microphone
Operating The Wired Microphone
Using External Equipment
Operating The External Speaker
Using The Aux Input
Using The Line Out Jack
1
1
2
4
5
6
7
7
8
8
Using The Cassette Deck
Each Part Name And Function
Playback
Fast For ard And Re ind
Recording
Tape Travel Modes
Cassette Tapes
Maintenance
Troubleshooting
Specifications
TOA Corporation
9
10
10
11
12
13
13
14
15

Features
A maximum of t o ireless microphones can be
used by mounting the optional ireless tuner
module in unit.
Po erful sound thanks to a 20cm 2- ay speaker.
Rated po er output of 15 atts and maximum
po er output of 20 atts.
Three-po er-source operation; AC mains, R20P
dry cells (8 pieces) and external po er supply.
Compartment ide enough to store a ired mic-
rophone ( ith 5-meter cable) and t o ireless
microphones.
Tone control that al ays provides clear speech
or music.
AUX input control.
It is possible to use the ired microphone jack
and AUX jack for both balanced and unbalanced
type plugs.
A digitally controlled auto-reverse cassette deck
enables long, continuous play ithout turning the
tape. (WA-641C only.)
The cassette deck employs a recording circuit
ith AGC function for easy recording of the
broadcast. (WA-641C only.)
Important
Po er source should be AC mains, R20P dry
cells (8 pieces) or external po er supply (12V
DC).
Do not install unit in a car parking under the
scorching summer sun or in locations here unit
is exposed directly to the sunlight. Also avoid in-
stalling unit close to heaters.
Take care that unit is not exposed to rain or that
raindrops should not enter unit as it ill cause
electric shocks and breakdo ns of unit.
Be sure to take hold of a plug to unplug the
po er cable from an AC outlet, other ise the
cable is disconnected.
When unit is unused, turn off po er s itch and
remove the po er cable from an AC outlet. Only
setting the po er s itch to OFF keeps unit con-
suming po er of about 4 atts.
If hairpins, coins, etc. enter unit, this can involve
dangers of electric shocks or breakdo ns. When
metallic stuff enters unit, be sure to set the po -
er s itch to OFF immediately, remove po er
cable and contact your nearest Toa dealer.
When carrying unit from one place to another, do
not give strong shocks to unit nor handle it
roughly.
Use a dry cloth to ipe do n the exterior of the
case. When the case is extremely dirty, clean
ith a soft cloth slightly damped in a neutral
cleanser. Never use benzine or thinner as its use
can deform or discolour the case.
- 1 -

Each Part Names And Functions
Carrying handle
Use this handle to carry unit from one place to another.
Note
This handle is only designed for carrying unit. Never use the
handle for the purposes of permanent suspension of unit.
Power indicator
When the po er s itch is set to ON, this lamp comes on.
Power switch
Press this s itch to s itch po er on. To s itch po er off, press
the s itch again.
Cassette deck (WA-641C)
Refer to page 9 for operation.
Line out jack (6 ohms, dBV)
Use this jack hen recording or connecting the external amplifier.
External speaker connector
This connector connects to the external speaker using an
attached plug.
Dry cell case
Eight of R20P (Size "D") is loaded. Observe polarities hen load-
ing dry cells.
External DC power input terminal
(220V/240V AC version)
* Set the voltage selector s itch
to 240V hen unit is operated
on 240V AC.
Wireless tuner module receptacle
A maximum of 2 ireless tuner modules (optional) can be
mounted in this receptacle.
Tuner cover
Be sure to fix this cover in place after mounting the tuner module.
(WA-641C)
Notch for power cable passage
Tuner cover fixing screw
Frequency marker
Attach the frequency markers supplied ith the tuner module.
Radio signal reception indicator
This lamp comes on hen unit receives a signal from the ireless
microphone.
Wired microphone volume control.
Mic 1/Mic 2 volume control
This is a volume control for both the ireless and ired mic-
rophones.
Aerial
Fully extend this aerial hen using the ireless microphone.
Mic 1 (wired mic) jack (6 ohms, -54dBV)
This jack can be used for both balanced and unbalanced type
plugs.
Mic 2 (wired mic) jack (6 ohms, -54dBV)
This jack can be used for both balanced and unbalanced type
plugs.
Wired microphone jack (6 ohms, -54dBV)
This jack only connects to the ired microphone, and can be
used for both balanced and unbalanced plugs.
Note
No ireless microphone can be used hen ired microphones
are plugged into Mic 1 and Mic 2 jacks. The volume control cor-
responding to each microphone is located immediately over the
jack.
AUX input jack (5 kohms, -2 dBV)
This jack can be used for both balanced and unbalanced type
plugs.
AUX input volume control
Bass/treble control
Rotation of this knob in the counterclock ise direction reduces
the bass response and turning it clock ise reduces the high fre-
quency response.
Compartment cover
Accessories are provided on the reverse side of this cover.
External speaker
plug x 1,
Single pole x 1,
Fuse x 1,
External DC plug x 1
Compartment
Po er cables, ired microphone, ireless microphones, etc. are
stored in this compartment.
- 2 - - 3 -

Power Source
AC MAINS OPERATION
Plug the supplied po er cable in an AC inlet, and
then plug it in an AC outlet,
Note
Unplug unit hen not in use.
DRY CELL OPERATION
Use eight of R20P dry cells. Observe polarities
hen loading them into the dry cell case. Re-
moval of the po er cable from an AC outlet after
loading the dry cell automatically s itches over
the po er source to the dry cell po er supply.
Note
If unit is not in use for t o eeks or longer,
take the dry cells out of unit to prevent
breakdo ns the dry cell leakage causes.
OPERATION ON EXTERNAL 12V DC (OPER-
ATIONAL ON 1 V to 16V DC)
A storage battery may be used by means of a
plug for external po er supply (standard acces-
sory). In making its connection, observe correct
polarity.
INPUT TERMINAL FOR EXTERNAL
DC POWER SOURCE
(WA-641C)
Storage battery (12V DC)
- 4 -

Mounting The Wireless Tuner Module
For tuner module, use the TOA model WTU-77
1. Remove the compartment cover.
2. Remove the tuner cover of the tuner receptacle.
3. Insert the tuner module into the length ise re-
ceptacle as sho n in Fig. 1, taking care so that
the module's top and bottom sides may not be
reversed. (See Fig. 1.)
Both the left and the right hand side recepta-
cles correspond to Mic 1 and Mic 2, respec-
tively.
Fig. 1. The WTU-770 module inserted into the receptacle
length ise.
4. Attach the frequency marker supplied ith the
module to the corresponding volume control.
(See Fig. 2.)
Note
Special cares are required so as not to insert
the tuner module into the rong receptacle
nor attach the frequency marker to the rong
volume control.
Fig. 2. Volume control on top panel
5. Fit the tuner cover in place after mounting the
tuner module. (See Fig. 3.)
* Be sure to fit the tuner cover in place to prevent
electric shocks or breakdo ns of unit, caused
hen metallic stuff enters unit.
Fixing scre
Fig. 3. Fitting the tuner cover
- 5 -

Operating The Wireless Microphone
Use the wireless microphone of which frequency is the same as that
of the tuner.
1.
2.
3.
4.
5.
Extend an aerial to its full length.
Place the po er s itch in the ON position.
Set the po er s itch of the ireless microphone
to ON.
*The radio signal reception indicator comes on.
Adjust the volume control for the desired volume.
Adjust the Bass/Treble control for the desired
tone.
(WA-641C)
Notes
1. The Mic 1 and Mic 2 volume controls are for
both the ireless and ired microphones. Con-
nection of the ired microphone to the mic-
rophone input jack makes it impossible to use
the ireless microphone on that input.
2. Take care about disturbing radio aves. When
the meeting amplifier is installed very close to
equipment that produce electric noise such as
industrial-use se ing machines and fluorescent
lamps, sound transmission from the ireless mic-
rophone can be interrupted. In such a case, put
the ireless microphone closer to the amplifier or
change the location of the amplifier.
3. Take care about a "null" spot. Signal dropouts
(momentary losses of reception) are caused by
interference and/or reflection of the transmitted
radio aves, a condition that constantly changes
as the ireless microphone is moved indoors.
The place producing the signal dropouts is cal-
led a "null" or "dead" spot. To solve this prob-
lem, position the amplifier further a ay from steel
desks or lockers or move it one to t o meters.
- 6 -

Operating The Wired Microphone
1.
2.
3.
4.
Set the po er s itch to ON.
Connect the ired microphone to the desired in-
put jack out of Mic 1, Mic 2 and ired mic jacks.
* The input sensitivity is 600 ohms and -54dBV.
Both of the balanced and unbalanced type
microphones can be connected to any of these
jacks.
Adjust the volume control for the desired volume.
* The volume control corresponding to each mic-
rophone is located immediately over the jack.
Adjust the bass/treble control for the desired
tone.
(WA-641C)
Using External Equipment
OPERATING THE EXTERNAL SPEAKER
External speaker connector
External speaker
connection plug
EXT. SP.
EXT. SP.
(WA-641C)
External speaker (20W, 8-16 ohms)
- 7 -
1. Connect an attached external speaker connec-
tion plug to the speaker cable.
Note
Use the speaker ith rated po er input of 20
atts or more and impedance of 8 to 16
ohms.
2. Insert the plug into the external speaker connec-
tor.
This plug connection disconnects the speaker
circuit in the meeting amplifier and only oper-
ates the external speaker.
This plug connection operates both the built-in
speaker and external speaker at a time.

USING THE AUX INPUT
AUX input jack
AUX input volume control
Bass/treble control
Phone plug
(WA-641C)
Record player (Ceramic cartridge type)
USING THE LINE OUT JACK
LINE OUT jack
Phone plug
To AUX input
(WA-641C)
Extension amplifier
- 8 -
The AUX input jack is used for connection of a re-
cord player or cassette deck. Adjust the AUX input
volume control for the desired volume. Tone control
can be performed ith the bass/treble control. The
input sensitivity is 500k and -20dBV. For connec-
tion, use a phone plug supplied. The balanced type
plug may also be used.
The LINE OUT jack connects to an extension ampli-
fier or cassette deck used for recording. For con-
nection of these equipment, use a phone plug sup-
plied. The output sensitivity is 60011 and 0 dBV.

Using The Cassette deck WA-641C
EACH PART NAME AND FUNCTION
Recording button/recording mode indica-
tor
Pressing this button causes a built-in red
LED to come on and puts unit in the record-
ing mode. Recording can be started hen
the direction selector button is pressed. For
details, refer to page 11.
Eject button
Pressing this button opens the dust cover
and allo s the tape to be loaded or re-
moved. Do not press this button during tape
run as this can damage the tape. When you
ant to remove the tape, be sure to press
the Stop button to stop tape motion before
pressing this button.
Dust cover (cassette holder)
Tape counter/Counter reset
button
Press this button to reset the
tape counter display to
"000".
Fast forward/Rewind but-
tons
Press this button to send the
tape for ard or in the re-
verse direction at top speed.
Stop button
By pressing this button tape
motion can be stopped.
Direction selector/indicator
This selector allo s the tape to travel in the
for ard or reverse direction
playback or recording. When pressed, the in-
dicator lights green to indicate the tape travel
direction.
for
- 9 -
Tape (playback level) con-
trol
Use this control to adjust the
output signal level during
playback.
Travel mode selector
This selector is used to
change over tape travel
modes
For
details, refer to page 12.

PLAYBACK
1.
2.
3.
4.
5.
6.
S itch po er on ith the tape control rotated ful-
ly counterclock ise.
After opening the dust cover by pressing the
Eject button
load the cassette tape ith the
exposed tape face do n.
Select the desired tape travel mode ith the
Travel mode selector. (For the tape travel mode,
refer to page 12.)
Press the preferred Direction selector
and the tape starts to travel and at the same
time, the Direction indicator comes on to indicate
the tape travel direction.
Adjust the Tape control for desired playback
level, turning the control clock ise.
To stop playback, press the Stop button
1.
2.
Press the preferred Fast for ard button
or
or
To stop the fast for ard operation, press the
Stop button
Tape motion stops.
Even hen the tape is not travelling, pressing
the Fast for ard button sends the tape running
at top speed.
If the Fast for ard button is pressed during re-
cording, the recording is stopped and the tape
is put in the fast for ard mode.
The tape travel is automatically stopped hen
the tape is fully re ound on the reel.
- 10 -
FAST FORWARD AND REWIND

RECORDING
Recording can be easily achieved without setting a recording level
with an AGC (Automatic Gain Control) being employed in the re-
cording circuit.
1.
2.
3.
4.
S itch po er on.
Open the dust cover by pressing the Eject but-
ton
and load the cassette tape ith the ex-
posed tape face do n.
Select the desired tape travel mode ith the
Travel mode selector. (For the tape travel mode,
refer to next page.)
Press the Recording button
The recording
mode indicator comes on and at the same time,
the t o direction indicators both blink.
Lights
Blink
Notes
When you use the tape of hich erasure pre-
vention tabs have been removed, the Record-
ing mode indicator or the Direction indicator
can fail to come on.
If one tab has been removed.
Recording mode indicator... Lights.
Direction indicator... Only either or the t o
blinks.
If t o tabs have both been removed.
Recording mode indicator... Does not light.
Direction indicator... Neither indicator
blinks.
Recording is only possible in the direction
indicated by the blinking direction indicator
if only either of the t o indicators is blink-
ing.
5.
Press the preferred Direction button, and that
pressed Direction indicator changes indication
from blinking to lighting (the other Direction in-
dicator goes out). At this point, you can begin
recording. (If you reset the tape counter display
to "000" or make a note of the number on the
counter before recording, you can come back
easily to the point from hich recording got
started after it is finished.)
6 .
When you ish to temporarily stop recording,
press the Stop button.
Note
When in the recording mode, all input signals
are recorded being mixed.

If you want to repeat recordings in the
same tape travel direction as that used in
the preceding recording.
Pressing the Recording button
during re-
cording puts unit in the standby mode. In this
event, the Recording mode indicator remains lit,
ith the Direction indicator in use s itched from
lighting to blinking.
Tape travel direction
Remains lit
Blinks
TAPE TRAVEL MODES
There are three tape travel modes.
1.
2.
3.
One- ay recording or playback.
T o- ay recording or playback.
Continuous repeat playback. The selection
of this mode during recording results in
t o- ay recording.
Playback
Mode
Travel
button
Actions
Tape run
Stops at tape end.
Tape run
Stops at tape end.
Tape run
Automatically reversed
at tape end.
Stops at tape end.
Tape run
Tape run
Stops at tape end.
Tape run
Automatically reversed
at tape
end.
Automatically reversed
at tape end.
Tape run
Tape run
Automatically reversed
at tape
end.
Automatically reversed
at tape end.
Tape run
- 12 -
2. To restart recording, press the Direction in-
dicator (button) that is blinking. The indicator
changes indication from blinking to lighting,
allo ing you to begin recording.
By repeating the above steps 1 and 2 different
programme sources can be recorded one after
another in the same tape travel direction.
When you ish to reverse the tape travel dur-
ing recording mode in the
direction, de-
press the recording button to place the deck
travel
on standby and then depress the
button. It is impossible to reverse the tape
to
motion from
during recording (for
protection of a recording mode in the
track).
Set the Travel mode selector to required position.
Travel mode selector
The table belo sho s actions resulting from op-
eration of both the Travel button and Travel mode
selector.
Recording
Mode
Travel
button
Actions
Tape run Stops at tape end.
Tape run
Stop at tape end.
Tape run
Automatically reversed
at tape end.
Stop at tape end.
Tape run
Tape run
Stops at tape end.
or
or

Maintenance
CLEANING THE HEAD SECTION
The head section is composed of the heads, cap-
stans and pinch rollers, and ith extended use
these parts accumulate dust, dirt and grease easily
as the tape runs. If this assembly gets dirty, this
do ngrades the sound quality and also leads to un-
stable operation. To prevent this, clean the head
section regularly ith a cleaning tape commercially
sold in the market or cleaning s abs slightly
damped in alcohol.
CAUTION
Never use a scre driver or metallic bar.
When cleaning ith the s ab, s itch po er off and
remove the dust cover (cassette holder) by lifting it
up.
Pinch roller
Capstan
Pinch roller
Recording/playback head
Erasing head
- 13 -
Do not store tapes in a hot moist place or close
to a television or speaker. To prevent deteriora-
tion of tape quality, loss of recording, and noise
generation, al ays store tapes in a cool, dry
place.
Cassette tapes are provided ith erasure pre-
vention tabs to avoid the accidental erasure of a
recording. If you ant to keep the recording, re-
move the tabs ith a scre driver.
Tab for side A Tab for side B
To re-record, cover the tab opening ith a dou-
ble layer of adhesive tape.
Adhesive tape
DEMAGNATIZING THE HEAD
The recording head becomes magnetized hen
you use the tape deck for prolonged periods of
time. This results in noise being generated and loss
or recording hich you ant to keep. The recording
head should therefore be demagnetized regularly
ith the head eraser commercially sold in the mar-
ket.
CAUTION
Do not grease any section as this causes
breakdo n of the deck.
Cassette Tapes
Our deck is designed for use ith the normal
tape only. Do not use chrome tapes or metal
tapes. If you use other tapes than the normal
tape, the sound quality ill deteriorate or pre-
ceding recording cannot be completely erased
hen recorded again.
Sounds can be harsh hen playing back a tape
recording ith the Dolby or similar noise reduc-
tion process. Use tapes recorded ithout the
noise reduction process.
Since the base of the C-120 tapes is thin and
easily damaged, they are not recommended for
use ith our deck. Use the C-46, C-60 or C-90
tapes.
Before using a tape, check to confirm if tape
slack exists. As tape slack causes the tape t ist
or tangle around the pinch heel and capstan,
take up slap, if necessary, by inserting a pencil
through the reel hub and turning it as indicated
in the figure belo .
Do not put any metallic stuff other than the
eraser or magnets closer to the head.

Troubleshooting
Symptom Confirmation
Remedy
Even hen po er s itch is set to ON,
po er indicator does not come on.
(No po er is supplied.)
No output sound.
[AC Mains operation]
Is po er cable plug inserted
into all AC outlet?
Plug po er cable into AC outlet.
[Dry cell operation]
Is polarity proper?
Re-load dry cells in proper
polarity. (See page 4.)
Volume control is placed in
minimum position?
Turn control clock ise.
Is aerial fully extended?
Fully extended aerial.
Is tuner module mounted?
Mount tuner module.
The radio signal reception does
not come on.
(Radio signal is not received.).
Is ireless mic po er s itch set
to ON?
Place mic po er s itch in ON
position.
Has ireless mic dry cell not
been exhausted?
Change dry cell ith ne one.
No output sound.
Is ired mic not connected?
Remove ired mic.
No playback sound.
Is playback level control set to
minimum?
Rotate control clock ise?
Recording button defies
attempts to depress it.
Have erasure prevention tabs
been removed?
Cover tab openings ith
adhesive tape.
Playback sound is distorted.
Recording cannot be erased
completely.
High frequencies are eak.
Is head section not dirty? Clean head section.
Has tape not been orn out?
Use other tape for playback. If
that tape produces no problem,
replace original tape ith ne
one.
Unstable tape travel.
Fast for ard/re ind speed is
slo .
Is there not tape slack?
Take up tape slack using
pencil.
If
ireless
mic is
used.
If
casette
tape
is
used.
- 14 -

Specifications
* Specifications are subject to change ithout notice
Accessories
Dust cover
Single pole plug
Plug for connection to external po er supply
Plug for connection to external speaker
Fuse (T500mA)
Operating instruction manual
1
1
1
1
1
1
TOA Corporation
PRINTED IN JAPAN
133-07-082-40
Model
Po er Requirement
Rated Output
AC
DC
Po er
Consumption
Frequency Response
Total Harmonic Distortion
Inputs Wired Mic
Auxiliary
Outputs
External
Speaker
Line out
Signal to Noise Ratio
Tuner Section (WTU-77 )
Aerial system
Receiving Sensitivity
Squelch Sensitivity
Receiving System
Signal to Noise Ratio
Cassette Section
Track Format
Recording System
Tape Speed
Wo & Flutter
FF/REW Time
Ambient Temperature
Dimensions (W×H×D)
Weight
Finish
WA-641
WA-641C
220V/240V AC (Selectable), 50 Hz
Dry Cells-8pcs. (R20P or D size), External DC 10 to 16V
15W at AC (Max 20W), 6W at DC
44W (Rated output)
1300mA
70 to 10k Hz 3dB deviation
Less than 3% (at rated output)
Mic 1, 2:—54dBv 600 ohms (S tichable ith ireless microphone)
-20dBV 500k ohms
8 to 16 ohms, more than 20W of rated input
0dBV 600 ohms
More than 70dB (at rated output)
Rod aerial
More than 80dB (20dBµV input, 1kHz Mod. 40kHz Dev.)
More than 75dB (20dBµV input, 1kHz Mod. 15kHz Dev.)
14dBuV (0dB = 1µV)
Superheterodyne System
More than 95dB (102dB: A eight) (60dBµV input, 40kHz Dev.)
More than 90dB (102dB: A eight) (60dBµV input, 15kHz Dev.)
2 track-1 channel (Mono)
AC bias
4.8cm/sec.
0.3% WRMS
Within 100 sec. (C60 tape)
-10 to 40 °C (14 to 104 °F) at AC
0 to 40 °C (32 to 104 °F) at DC
366×456×200 mm (14.4" × 18.0" × 7.9")
7.3 kg (16.1 Ibs) 8.3 kg (18.3 Ibs)
Light green (ABS resin)