TOA Electronics W-906A - Manual (Page 6)

Step 6. Fixing the amplifier
Fix the amplifier to the back box with screws
after connecting the power cable and the
speaker cable.
Step 7. Selecting output impedance
Select appropriate output impedance that matches the speaker to be used.
Class 2 wiring may be used.
Since these outputs consist of 8
Ω, 25 V and 70 V via the output transformer (matching transformer) and
direct output of 4
Ω, the connecting method differs in each case. See the following diagram.
Note: Impedances indicated below imply total speaker system (load) impedances.
• When connecting speakers to any one of the outputs of 8
Ω, 25 V or 70 V (BALANCED TRANSFORMER
OUTPUT); connect as illustrated below.
Note
In this case, the LOW-CUT SWITCH should be in "CUT" position. The
amplifier is characteristically flat even in the low frequency range.
Therefore, in TRANS OUTPUT, the acoustic effect and frequency-
response 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 2k 4k 8k 16k
IN EQUALIZER
OUTPUT FUSE COMPRESSOR
INPUT 4 INPUT 5 INPUT 6 MASTER
12 6 0 6 12
12 6 0 6 12
COM 8 Ω 4 Ω 25V 70V
OT
IN + –
a b c
a
b
c
a
b
c
8
Ω
or
10.4
Ω (25 V line)
or
83
Ω (70 V line)
+
Insert shorting bar
between 4
Ω and OT IN
SPEAKER
OUTPUT
COM 8 Ω 4 Ω 25V 70V
OT
IN + –
a b c
8
Ω
or
5.2
Ω (25 V line)
or
41
Ω (70 V line)
+
Insert shorting bar
between 4
Ω and OT IN
SPEAKER
OUTPUT
CUT
LOW-CUT
FLAT
Place the LOW-CUT SWITCH
in "CUT" position
[W-906A]
Change cable connection for required impedance
according to the speaker used.
[W-912A]
Change cable connection for required impedance
according to the speaker used.
COM 8 Ω 4 Ω 25V 70V
OT
IN + –
Remove shorting bar
SPEAKER
OUTPUT
4 Ω