1B 2B 3B 4B 5B 6B 7B - Input Jacks For Microphones : (Use 6.3mm phone Plug) Input jacks for receiving signals from low impedance microphones.

14 12V DC Terminal : For connecting 12 Volt Car Battery.

15 Combined Terminal Strip For Pre-Amp And Line Output.

Bass Control Position For Driver Units : It may be noted that driver units and reflex horns cannot reproduce low frequencies (below 250Hz). If the power from the amplifier at frequency below 250Hz is fed, it will only heat-up the Diaphragm, as driver units and Reflex-horns cannot convert this into sound

Caution : When driver units are connected to the amplifier bass control must be used at "O" position (preferably at below "o" position i.e.-20r-4position).

Treble : This controls the tonal quality of the high frequencies produced by stringed musical instruments like Violin, Sarangi and Sitar etc. and to some extent female human voice. When the control is rotated clockwise (Above "O" positions), it will increase the intensity (boost) of high frequencies, when lowered (below "O" position), it will reduce the intensity (cut) of high frequencies. Over boosting of high frequencies is not desirable therefore avoid using this control to maximum boost position.

Setting Of Master Control : Master control is provided for overall adjustment of all input signal (mixed). in other words, it acts as a 'GATE' between the signal coming from various microphones and AUX inputs and the output stage of the amplifier. Unless this 'GATE' is opened no output signal can pass through. For ensuring low hum and better overload margins, necessary for good performance, the master control should generally be set and operated at 6or higher position.

Led Array For Output Level Indication : An Array consisting of 7 LEDs(5green & 2 red ) is provided to indicate the working condition of the amplifier. / When these LEDs  are flickering, it shows that the signals from the input channel (microphones etc.) are being fed to the output stage of the amplifier and further being passed on to the output terminals. / It also indicates roughly, the power output that is being passed on to the loudspeakers by the amplifier. When 7th LED (red) glows continuously it shows a condition of 'overloading; The volume on the master control should immediately be reduced until the 7th LED starts flickering instead of glowing continuously. When these LED  are flickering, and no sound is reaching the loudspeakers, check the loudspeakers connections and wiring there of. In case of SSA-180 5LED s (3Green and 2 Red are provided.)

Line Output : A line output of 400mV has been provided through an RCA jack marked Line output on the rear panel for connecting another amplifier or booster. The line output is after bass & treble control circuit of the amplifier and the setting of these controls does affect the line output signal. When connected to a booster amplifier.

ARCH portable Megaphone MP-03, MP-05, MP-08, MP-09

Etra MP-03, MP-05, MP-08, MP-09 are high powered, shoulder type transistorized Megaphone with capability to cover a range of 600meters in noisy surroundings. It is a self contained unit and is ready to use in any emergency for public address applications,

Parts & Their Functions : Cell replacement cover : Dry cells can be easily replaced by removing this cover./ 2. Nut:; To hold cell cover in place./ 3. shoulder pad: Makes the carrying of megaphone very convenient. / 4. Tapped hole: For mounting on stand./ 5. Power ON/OFF switch : press to talk type. / 6. Microphone mouthpiece. / 7. Volume control. / 8. Microphone peg : Hook up the microphone on to this, for convenience. / Crowed control, Fire Fighting, Rescue Operations, Construction Sites, Announcements, Sports Events, Electioneering, Field Publicity etc. / 9. Microphone peg on belt : convenient place for hanging microphone during pauses in operation.

1. For inserting the battery cells, remove the cell replacement cover by unscrewing the nut. The cell housing will now be access sable. Insert 8 medium size cells (UM-2) with the polarity in accordance with the diagram in the housing. Replace the cover and tighten the nut. / 2. Depress the talk switch (5) of the microphone. / 3. Adjust the volume control (7) of the microphone to give the desired output. If feedback and howling occur as soon as the talk switch (5) is depressed, reduce the volume. / 4. The talk switch (5) can be locked on the ON position by depressing it and then pushing it upwards. To switch off, push the talk switch downwards.

13.Connecting Cassette Player : For playing recorded music from a cassette player, Jacks marked MIC-5/AUX-1 and MIC-6/AUX-2 are provided. / The volume controls and the switches for selection of MIC-5 or AUX-1 MIC-6 or AUX-2 operation are on the front panel. / AUX-1 INPUT : This input has a sensitivity of 70mV /1Mohms suitable for cassette player with low output while AUX-2 has a higher sensitivity of 150mV and is suitable for cassette player with high output. / AUX-2 INPUT : are also suitable for connecting Mixer Amplifier, Echo Mixer etc.

To obtain maximum power output and best quality performance from the powerful Amplifier it is necessary that only very high quality and professional grade microphones of ARCH type selected and used. Only Lo-Impedance microphones (2000ohms to 1000ohms) be used. All ARCH microphones are Lo-Impedance type and perfectly match able to this amplifier. If by mistake a microphone having high impedance is used, chocking sound will occur. All mikes and aux. inputs are with 6.3mm(jack) Only high quality phone plug(6.31/4") should be used. Up to 6 microphones can be connected, 4 independent and 2 alternate (MIC-5 and MIC-6) to AUX. for input 6.3mm jacks (see No.13,14,15 on the rear panel) are provided. these jacks have in built shorting switch. The phone plug(p-38) must be firmly inserted in the jacks to make this switch open the input circuit. AUX-1 & AUX-2 have match able impedance and sensitivity for cassette player, radio tuner mixer, preamp, Echo mixer, organ synthesizer, Electric guitar. Extending Microphone Cable : If longer cable (say 60ft. or even up to 100ft.)is required, use ARCH twin-core shielded Extension cable fitted with suitable connectors, Use of substandard cable will pick up stray noise and unwanted hum and signal. Make sure that the MIC cable is kept away from the loudspeaker wires and AC Mains cables.

Connecting & Operating Microphones : Attach the cables of the respective microphones and firmly insert the jack plug into the MIC sockets provided at the rear of the amplifier. To identify various microphones and their corresponding cables. use matching colored stickers at both ends of the microphone cables. MIC-1, MIC-2, MIC-3 & MIC-4 channels are provided with a 3-position switch marked as OFF-CUT-FLAT' This switch when at OFF position temporally switches off any microphone without disturbing its volume level. At Cut position, it tapers off the low frequencies resulting in reduction of howling and feedback thus permitting more volume to be opened on the amplifier. The ' FLAT' position offers full frequency offers full frequency response for reproduction of 'live' music or orchestra programmed. Red LED shall glow at CUT and FLAT position to indicate that particular MIC channel is ON. With all the MIC volume controls set at "O" position, raise the Master Volume Control to 7 or 8 position. The' BASS' and TREBLE' controls should be set at the appropriate positions. (For details see explanation). Move the volume control of MIC-1 channel slowly to get desired sound level but below the point where howling and feedback occurs. Now switch MIC-1 to 'OFF' position and repeat the same for MIc-2, MIc-3 and soon. Before switching "ON" all the microphones, reduce the Master control by one or two points. This is to which might occur and cause damage to the speakers. Now raise the master control slowly to get the desired level of sound from all the microphones.

Microphone Connection : four independent microphone inputs have been provided through jacks on the front panel. MIC-4 input may be used by keeping the MIC/TAPE -HI selector switch at MIC position. Microphone inputs are unbalance low impedance usable with microphone of impedance 200ohms to 600ohms (LO-Z). In case microphones with both high and low impedance are used, be sure that switch on the microphone is at LOW position. Microphone with up to 30 meter long cable can be used. Always use good quality shielded cables. For good intelligibility of sound, the microphone should be placed at least 20cms away from the speakers mouth. keeping the microphone too close to the mouth will result in distortion of sound and may even cause damage to the diaphragm of the microphone. Note: MIC-3 and AUX inputs are connected in parallel and have common volume control. Hence they should not be connected simultaneously.

Phone connection: An AUX input is provided through a 2-Pin terminal strip at the rear. Connect the LIVE and SHIELD of the pickup wire to LIVE and EARTH respectively on the strip.

Tape Recorder Connection : The Aux input can also be used for connecting a cassette tape recorder. For a good performance and low distortion, the volume control of the cassette tape recorder should be kept at a low position.

Speaker Connections : Low Impedance : Speaker impedance taps of 4ohms 8ohms and 16ohms have been provided at the rear. It is recommended to connect at least 2driver units while using the amplifier on AC mains or car battery. Use of 23/36 or thicker cable is recommended.

Connecting One Speaker : Two driver units of 16ohms impedance each should be connected in parallel between COM and 8ohms taps of the amplifier as the resultant impedance of the parallel combination is 8ohms. Similarly two unit horn combinations of 8ohms impedance each should be connected in parallel between COM and 4ohms taps.

Phasing Of  Loudspeakers/Units : When two or moor speaker/units are installed in the same area and are facing in the same direction, it is essential that their cones/diaphragms move in unison. otherwise, the sound output of one speaker will cancel the sound output of the other. To avoid any mistake, the terminals of all driver units are marked L1&L2. For correct wiring, refer to the sketches of loudspeaker connections.

Warning : Connect a set of speaker to any one of the low impedance taps 4ohms or8ohms or16ohms at a time.

AC Mains Operation : Set all volume controls to "O" position and keep the power and dry Bat switch at off position. Connect the speakers and required inputs. Plug in the AC power supply cord to the nearest AC mains socket and put the power switch ON position. The pilot LED should start glowing. Adjust the volume and tone controls to the desired level.

Car Battery Operations : Keep the power and Dry Bat switches at OFF position and make the required input and speaker connections. Connect a 12V Car Battery to the 2-Pin strip at the rear. Be sure that the positive pole of the battery is connected to the screw terminal marked(+) and the negative pole to the screw marked(-) The pilot LED should glow. In case it does not glow check battery polarity. Note that the car battery operation is not controlled by the power switch To switch OFF the amplifier on car battery operation, disconnect supply to battery terminals at the rear. Make sure that the battery is fully charged.

Dry Battery Operation : Keep the Dry-Bat switch at OFF position. Turn the amplifier upside down and remove the base plate. Insert 16 standard size torch cells (UM-1) in correct position indicated on the cell tryst and refax the base plate tightly. After connecting inputs and speakers, put the Dry Bat switch at ON position. The pilot LED should glow. Operate the amplifier.