Operating Instructions TOA 900 SERIES II P-906MK2 P-912MK2 P-924MK2 POWER AMPLIFIER P-906MK2 P-912MK2 P-924MK2 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. TO REDUCE THE RISK OF ELECTRICAL SHOCK, DO NOT REMOVE COVER. NO USER SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
Contents General description Features Nomenclature Front panel Rear panel Input connections Output connections Rack mounting Operation Volume adjustment Installation Servicing Specifications 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 Amplifiers deliver up to 60 watts, 120 watts and 240 watts of power respectively at less than 0.
Nomenclature Front Panel P-906MK2, P-912MK2 P-924MK2 Power Switch Peak Indicator LED Applies line power. Two-position push button Red LED lights when amplifier approaches switch for on/off modes. clipping level. If steady lit, the input level control should be turned down until the LED flashes. Protection Indicator LED Remains lit for about 5 seconds after power switch is turned ON. Master Volume Control Adjust gain of input. Power Indicator LED Green LED lights when the power is switched "ON".
Rear Panel P-906MK2, P-912MK2 P-924MK2 AC Power Cord Input Level Switch Selects input sensitivity. Place in "1V" (0 dBV) Connects to power source. AC Outlet (Unswitched) Provides AC power for auxiliary equipment with power consumption of up to 500W. position when normally used as a power amplifier. Note: The position of INPUT-LEVEL SWITCH Impedance Select Switch should be changed according to modules Selects the desired impedance.
Input Connections Two types of input terminals are provided on the rear for input connections. (1) 2P terminal (marked HOT, COM) It is provided for direct input (unbalanced, 10k ohms) without using plug-in module. This terminal is directly connected with a potentiometer inside. (2) Plug-in module input Select the desired module according to application. DIRECT INPUT TERMINAL and MODULE INPUT are not usable simultaneously.
Output Connections The speaker outputs of the amplifier are 4 ohms, 8 ohms, 25V and 70V. Connect speakers to any one of these outputs. Class 2 wiring may be used. There are two types of output ; 8 ohms, 25V and 70V via output (matching) transformer 4-ohm direct output. The connecting method differs in each case. Refer to the following diagrams. Note : Impedances indicated below imply total speaker system (load) impedances.
To connect speakers to 4-ohm output (UNBALANCED DIRECT OUTPUT) (P-906MK2/P-912MK2) 4-ohm Loosen the screw. Place the impedance switch in 4-ohm position. Tighten the screw. (P-924MK2) Remove shorting bar. 4-ohm Rack Mounting To mount the amplifier in a standard 19" equipment rack, use the optional MB-25B, MB-35B rack mounting bracket. Remove 4 screws securing case. MB-25B (P-906MK2, P-912MK2) MB-35B (P-924MK2) Amplifier Fix the brackets with attached 4 screws.
Operation After all connections are made, turn power switch ON, illuminating the Power Indicator LED. The amplifier comes into operation approximately 5 seconds after the power is turned on. Volume Adjustment Obtain desired output level by adjusting the master volume control. For normal music playing or announcement, adjust the master volume control until the normal LED intermittently lights. Sound quality is deteriorated when the peak LED remains lit.
Specifications P-906MK2 Type Frequency Response P-924MK2 120W RMS (D) 240W RMS, (T) 220W RMS Power amplifier Output Power Power Band Width P-912MK2 60W 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 Total Hamonic Distortion 0.01% at 1 kHz, rated output Inputs One Input Ports : Port accepts any input module except T-01.
Appearance (P-906MK2/P-912MK2) Front View 420 Rear View 320 17 – 10 – 358 Side View Top View
Appearance (P-924MK2) Front View 420 Rear View Top View 17 – 11 – 334.2 298.
TOA Corporation KOBE, JAPAN PRINTED IN TAIWAN 133-12-116-60