Toa P-906MK2 User manual

TOA 900 SERIES II
POWER AMPLIFIER
Operating Instructions
P-906MK2
P-912MK2
P-924MK2
P-906MK2
P-912MK2
P-924MK2
TO REDUCE THE RISK OF ELECTRICAL
SHOCK, DO NOT REMOVE COVER.
NO USER SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED
SERVICE PERSONNEL.
THE LIGHTNING FLASH WITH
ARROWHEAD WITHIN A TRIANGLE IS
INTENDED TO TELL THE USER THAT
PARTS INSIDE THE PRODUCT ARE A
RISK OF ELECTRIC SHOCK TO
PERSONS.
THE EXCLAMATION POINT WITHIN A
TRIANGLE IS INTENDED TO TELL
THE USER THAT IMPORTANT
OPERATING AND SERVICING
INSTRUCTIONS ARE IN THE PAPERS
WITH THE APPLIANCE.
Plea e follow the in truction in thi manual to obtain the optimum re ult from thi unit.
We al o recommend that you keep thi manual handy for future reference.
TOA Corporation

ontents
General de cription
Feature
Nomenclature
Front panel
Rear panel
Input connection
Output connection
Rack mounting
Operation
Volume adju tment
In tallation
Servicing
Specification
Appearance (P-906MK2/P-912MK2)
Appearance (P-924MK2)
2
2
3
4
5
6
7
8
8
8
8
9
10
11
General Description
The TOA P-906MK2, P-912MK2 and P-924MK2 Power Amplifier deliver up to 60 watt , 120 watt and 240
watt of power re pectively at le than 0.5% total harmonic di tortion (THD) from 20 to 20,000 Hz
(tran formerle 4-ohm output). The power amplifier have a high-impedance direct input and an input port
(edge connector) to accept one plug-in module. Module election i determined by application among the
TOA plug-in module .
The power amplifier have a low-cut witch for a cutoff frequency of 60 Hz, and an input-level witch for input
en itivity of 1V (0 dBV) or 100mV (–20 dBV). Output terminal provide connection for 4-ohm and 8-ohm
peaker , plu 25-volt and 70-volt peaker di tribution outlet . With plug-in module , the power amplifier
may be u ed a a PA amplifier.
The power amplifier can be rack mounted by u ing optional rack mounting bracket MB-25B(P-906MK2,
P-912MK2) and MB-35B(P-924MK2). The optional perforated panel PF-511 provide uitable ventilation,
fini hed in color to match the power amplifier .
Features
1. Wide frequency re pon e : 20 ~ 20,000 Hz ± 1 dB
2. Low di tortion and noi e level
3. Excellent output regulation
4. A full range of plug-in module
5. Self-protecting circuitry de ign
6. Varied output impedance : 4 ohm , 8 ohm , 25 and 70 volt
7. Input level witch ( electable 1000 mV/100 mV)
8. Portable or rack mounting type
– 2 –– 2 –

Nomenclature
Front Panel
P-906MK2, P-912MK2
P-924MK2
Power Switch
Applie line power. Two-po ition pu h button
witch for on/off mode .
Power Indicator LED
Green LED light when the power i witched
"ON".
Signal Indicator LED
Green LED light when more than -30 dB ignal
level i fed to the input by mean of the ma ter
volume control.
Normal Indicator LED
Yellow LED light when fed to the proper ignal
level.
Peak Indicator LED
Red LED light when amplifier approache
clipping level. If teady lit, the input level control
hould be turned down until the LED fla he .
Protection Indicator LED
Remain lit for about 5 econd after power
witch i turned ON.
Master Volume ontrol
Adju t gain of input.
– 3 –

Rear Panel
P-906MK2, P-912MK2
P-924MK2
A Power ord
Connect to power ource.
A Outlet (Unswitched)
Provide AC power for auxiliary equipment with
power con umption of up to 500W.
Impedance Select Switch
Select the de ired impedance.
Enable unbalanced output of low impedance
when thi witch i et to "DIRECT".
Output terminals
Connect to peaker .
Module Input Port
Accept optional PLUG-IN MODULES.
Application determine type of module.
For detail , refer to Plug-in Module In truction
Manual.
Low- ut Switch
Cut off unnece ary low frequency.
Input Level Switch
Select input en itivity. Place in "1V" (0 dBV)
po ition when normally u ed a a power
amplifier.
Note: The po ition of INPUT-LEVEL SWITCH
hould be changed according to module
u ed or equipment connected to DIRECT
INPUT TERMINAL.
Direct Input Terminal
Connect directly to external equipment without
u ing module .
Unbalanced 10k ohm .
A Fuse (250V, 7A)
D Fuse (250V, 8A)
D Fuse (250V, 8A)
Protect amplifier from exce ive current drain.
Replace only with ame type fu e.
Refer to qualified ervice per onnel if fu e blow
repeatedly.
– 4 –

Input onnections
Two type of input terminal are provided on the rear for input connection .
(1) 2P terminal (marked HOT, COM)
It i provided for direct input (unbalanced, 10k ohm ) without u ing plug-in module. Thi terminal i
directly connected with a potentiometer in ide.
(2) Plug-in module input
Select the de ired module according to application.
DIRECT INPUT TERMINAL and MODULE INPUT are not u able imultaneou ly.
Plug the module into the INPUT PORT, liding it between the guide rail and ecure with two crew .
When INPUT PORT i not occupied, cover the PORT with the blank panel and ecure it with crew .
Be ure that INPUT-LEVEL SWITCH i in the proper po ition for the module u ed or the equipment
connected to DIRECT INPUT TERMINAL.
When the P-906MK2, P-912MK2 or P-924MK2 i u ed in combination with a mixer preamplifier or erve
a an incremental power amplifier, normally place INPUT-LEVEL SWITCH in "1V (0 dBV) po ition.
AUTION: Module hould not be in erted or
removed while the amplifier i turned
on.
– 5 –

Output onnections
The peaker output of the amplifier are 4 ohm , 8 ohm , 25V and 70V.
Connect peaker to any one of the e output .
Cla 2 wiring may be u ed.
There are two type of output ;
8 ohm , 25V and 70V via output (matching) tran former
4-ohm direct output.
The connecting method differ in each ca e. Refer to the following diagram .
Note : Impedance indicated below imply total peaker y tem (load) impedance .
To connect speakers to outputs of : 8 ohms, 25V or 70V (BALAN ED OUTPUT)
(P-906MK2/P-912MK2)
8-ohm
10.4-ohm(P-906MK2)/
5.2-ohm(P-912MK2)
25V line
83-ohm(P-906MK2)/
41-ohm(P-912MK2)
70V line
Loo en the crew.
Place the impedance witch in 8-ohm po ition.
Tighten the crew.
(P-924MK2)
8-ohm
2.6-ohm
25V line
21-ohm
70V line
In ert horting bar between 4
and OT lN.
Note : Low-cut witch hould be in "CUT" po ition.
Cut off unnece ary low frequency in TRANS OUTPUT to obtain be t acou tic condition. The
900MK2 erie amplifier are characteri tically flat even in the low frequency range. Thu , in TRANS
OUTPUT the acou tic effect and frequency-re pon e characteri tic may be altered.
– 6 –

To connect speakers to 4-ohm output (UNBALAN ED DIRE T OUTPUT)
(P-906MK2/P-912MK2)
4-ohm
Loo en the crew.
Place the impedance witch in 4-ohm po ition.
Tighten the crew.
(P-924MK2)
Remove horting bar.
4-ohm
Rack Mounting
To mount the amplifier in a tandard 19" equipment rack, u e the optional MB-25B, MB-35B rack mounting
bracket.
Remove 4 crew
ecuring ca e.
MB-25B (P-906MK2, P-912MK2)
MB-35B (P-924MK2)
Fix the bracket with attached 4 crew . The length
of crew hould not exceed 12mm (1/2").
PF-511 perforated panel (1-unit ize)
U e the perforated panel PF-511 to provide pace for ventilation,
when two or more unit are mounted in an equipment rack.
Contact your local TOA dealer for the perforated panel PF-511.
Amplifier
– 7 –

Operation
After all connection are made, turn power witch ON, illuminating the Power Indicator LED. The amplifier
come into operation approximately 5 econd after the power i turned on.
Volume Adjustment
Obtain de ired output level by adju ting the ma ter volume control. For normal mu ic playing or
announcement, adju t the ma ter volume control until the normal LED intermittently light . Sound quality i
deteriorated when the peak LED remain lit.
When the power amplifier i u ed in combination with a mixer preamplifier, adju t total gain at the mixer
preamplifier with the gain etting of power amplifier at maximum.
Never block ventilation hole .
The amplifier hould never be placed in area
expo ed to direct unlight.
with high humidity or du t level .
with high ambient temperature .
u ceptible to vibration.
with poor ventilation.
adjacent to heat-generating equipment.
AUTION : Do not remove the ca e or you may encounter an electric hock.
Note : When the temperature of heat ink exceed 105 °C the protection circuit i activated and the output i
di connected from the circuit. Output i automatically re tored when the temperature return to normal
operating parameter.
Servicing
Unpacking
Upon receipt of the amplifier hipment, plea e in pect for any damage incurred in tran it. If damage i
found, plea e notify your local TOA repre entative and the tran portation company immediately.
State date, nature of damage, whether any damage wa noticed on the hipping container, prior to
unpacking. Plea e give waybill number of hipping order.
Failure
Should amplifier fail, contact your neare t TOA authorized contractor or ervice center.
– 8 –

Specifications
Type
Output Power
Power Band Width
Frequency Re pon e
Total Hamonic Di tortion
Input
Input Sen itivity/Impedance
Output (T)=Tran former
(D)=Direct
Output Regulation (1 kHz)
Signal to Noi e Ratio
(Band Pa 20 -20,000 Hz)
Control
Indicator
Protection
Connector
Power Con umption
Temperature Range
Dimen ion (W) x (H) x (D)
Weight
Color
Standard Acce orie
Other Feature
P-906MK2 P-912MK2 P-924MK2
Power amplifier
60W RMS 120W RMS
(D) 240W RMS,
(T) 220W RMS
(D) 20 ~20,000 Hz, 0.5% THD
(T) 50 ~20,000 Hz, 0.5% THD
(D) 20 ~20,000 Hz, ± 1 dB
(T) 20 ~15,000 Hz, ± 1 dB, (T) 20 ~20,000 Hz, +1 dB, -3 dB
0.01% at 1 kHz, rated output
One Input Port : Port accept any input module except T-01.
One Direct Input
Note : U e of direct input prohibit u e of modular input port.
Input Port : 100 mV or 1000 mV ( witchable)/10k ohm
Direct Input : 100 mV or 1000 mV ( witchable)/10k ohm
Main (T) : 8 ohm , 25 & 70 volt , balanced
Main (D) : 4 ohm , unbalanced
(D) Le than 0.5 dB, no load to full load
(T) Le than 1.0 dB, no load to full load
Input level witch in 0 dBV (1000 mV) po ition : 108 dB
Input level witch in -20 dBV (100 mV) po ition : 90 dB
1 Input gain control
1 Input level witch
1 Power ON/OFF witch
1 Low-Cut witch
1 Power LED, 1 Protect LED, 1 Signal LED, 1 Normal LED, 1 Peak LED
Self-protection, with AC fu e (in ide)
Self-protection, with 2AC
fu e (1 in ide)
and 2DC fu e
Input
Output
AC outlet
AC power cord/plug
Card-edge connector and crew-terminal trip
Screw-terminal trip
3-pin grounding type
SJT, 3-prong type
100W
180W
120V/3A
-10°C~+60°C [12°F~140°F]
420 x 99.1 x 358 mm
[16.5 x3.9x 14.1 in.]
9.1 kg [20.1 Ib.]
10.9kg [24.0 Ib.]
420 x 151.3 x 334.2 mm
[16.5 x 6.0 x 13. 2 in.]
19.5kg [43 Ib.]
Black
1 Volume control cover (YA-920)
Output di connected for approx. 5 econd after witching power on.
* Specification are ubject to change without notice.
– 9 –

Appearance (P-906MK2/P-912MK2)
Front View
420
Rear View
Top View
Side View
320
358
17
– 10 –