Alto ELVIS Schematic

Service Manual

ELVIS ACTIVE SPEAKER CABINET

MODEL: ELVIS10A/ELVIS12A/ELVIS15A/

ELVIS12MA/ELVIS12SA/ELVIS15SA

LTO

www.altoproaudio.com

Version 1.0

CONTENTS

1. Warning

2. Technical Specification & Transistor Packages

3. Test Procedure & Setting

4. Schematic Diagram

5. Spare Part List

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1. Warnning

Service must be carried out by ALTO qualified personnel only.

Unqualified service personnel used in the warranty time of the product, produce a falling of the warranty.

Schematic diagram and part list of the devices may be subject to change without immediate notice.

When to replace any components, use only original spare parts.

All the resistors are at 1/8 Watt, all the electrolytic capacitors are at 25V, unless otherwise specified.

The symbol used for the resistors are R (ohm) and for the capacitors are U (microfarad).

2. Technical Specification & Thansistor Packages

ELVIS10A ELVIS12A ELVIS15A ELVIS12MA

Output Power IHF

Output Power RMS

Max SPL at 1mt

Input Sensitivity

Input Impedance

Connectors

Subsonic Filter

Protections

External Control

Power Supply

Net Weight lbs/kg

Gross Weight lbs/kg

Shipping Volume

Output Power IHF Output Power RMS Max SPL at 1mt Input Sensitivity Input Impedance Connectors Subsonic Filter Protections External Control Power Supply Net Weight lbs/kg Gross Weight lbs/kg Shipping Volume

150Watt IHF 250Watt IHF 350Watt IHF 250Watt IHF

120Watt RMS 180Watt RMS 250Watt RMS 180Watt RMS

117.5 dB ( IHF Power ) 121 dB ( IHF Power ) 123 dB ( IHF Power ) 121 dB ( IHF Power )

Line 0dB/0.775V/Mic-10 at -45dB

30kOhms Balanced - 15kOhms Unbalanced

Mic on XLR/Line Input on Combo/Line-Mix Output on XLR

30Hz - 24dB/oct. 30Hz - 24dB/oct. 30Hz - 24dB/oct. 30Hz - 24dB/oct.

Soft - Start DC voltage protect - compressor

Mic Gain - EQ-High-Mid-Low-Volume-Ground Switch

40.12lbs/18.2kg

46.83lbs/21.24kg

4.58CFT

121 dB ( IHF Power ) 123 dB ( IHF Power )

60.36lbs/27.38kg

67.19lbs/30.48kg

6.15CFT

50.95lbs/23.11kg

58.89lbs/26.71kg

6.03CFT

ELVIS12SA ELVIS15SA

250Watt IHF 350Watt IHF

180Watt RMS 250Watt RMS

Line 0dB/0.775V

30kohms-input/600ohms-output

L/Mono-R IN on XLR/L-R OUT on XLR

Electronic Crossover 125Hz at 24dB/oct.

Soft start-DC voltage protect -compressor

Volume - Stereo/Mono & Ground Swicth

230Volt/115Volt 50/60Hz

230Volt/115Volt 50 / 60Hz

62.83lbs/28.5kg

71.52lbs/32.44kg

7.35CFT

49.54lbs/22.47kg

56.92lbs/25.82kg

6.10CFT

76.68lbs/34.78kg

85.72lbs/38.88kg

8.67CFT

Transistor Packages

TO92 2SC1815, 2SA1015:

1=Emitter 2=Collector 3=Base

2N5401, 2N5551:

1=Emitter 2=Base 3=Collector

TO126 MJE340, MJE350, MJE802:

1=Emitter 2=Collector 3=Base 4=Collector

TO220 MJE15030, MJE15031:

1=Base 2=Collector 3=Emitter 4=Collector

TO218 TIP35C, TIP36C:

1=Base 2=Collector 3=Emitter 4=Collector

TO264 2SC5200, 2SA1943:

1=Base 2=Collector 3=Emitter 4=Collector

3. Test procedures & Setting

CAUTION

Before removing or installing the Power amplifier, switch off and disconnect the power cord from the AC mains socket. When you have visible

the components, discharge the capacitor before to start the maintenance.

When you connect the probe to the output of amplifier, insulated the earth of the oscilloscope, to prevent short circuit during the test.

The Power Amplifier work in Class H and use a dual bipolar rail configuration, one low rail(+/-Vcc1)RMS power and second high rail (+/-Vcc2)

IHF power.

Read the Service Manual before to proceeding to any operation.

VISUAL INSPECTION

Before to proceed with maintenance, look the condition of the product, for define the entity of the damage and probably cause.

Disconnect the power amplifier from the cabinet and look if appears an evident mechanical damage or an assembled circuit burn or break.

Verify the integrity of acoustical component, disconnect from the passive crossover and measure with a digital multi-meter the resistor of the

voice coil of the woofer Rcc=3.5/6 ohm and of the driver Rcc=6 ohm. If you measure a resistor with less value the voice coil is in short circuit, if you measure open circuit the voice coil is break off.

OPTIMUM TEST INSTRUMENT

FUNCTION GENERATOR

DUAL-CHANNEL OSCILLOSCOPE

DIGITAL MULTIMETER

FAN LOAD RESISTORS 4 OHM/400W

VARIAC(0-250VAC)

POWER MODULE SETUP

Remove the transformer with your bracket, unscrew the 8 screw M4 without remove the electrical connection.

Fix the heat sink with PCB amplifier on the chassis with 2 screw, for prevent casual damage.

Turn full anticlockwise the knob of Main Volume, for prevent the signal noise at the Input of the amplifier.

Connect the digital multi-meter set in Vcc, across the R33=0.22R 5W, if you have a analog tester set at a correct scale and respect the polarity. Set the trimmer VR1 used for the idle current, in full anticlockwise position, for prevent the damage of the amplifier, during the setting.

Set the VARICAL at 0VAC and connect from the 230VAC mains socket an the power amplifier under test, verify that the socket and the power cord included the earth ground connected.

ADJUSTMENT

Switch ON the power amplifier and increase slowly with the Variac, the AC voltage until 230V.

See on the digital multi meter and read a value near to 0 mV(Vcc), turn in clockwise the trimmer VR1 until to read 5mV(+/-0.5mV) across the R33, now wait until the temperature rise, in the same time also the voltage rise, turn in anticlockwise the trimmer VR1 until to read again 5mV(+/-0.5mV) across R33, read the same value also on R34 (+/-1mV) and verify the stability of the value, do not risk a thermal drift, repeat the setting procedure.

When you are sure of the stability of power module, switch OFF the power amplifier disconnect the multi meter, assemble the transformer with bracket on the chassis with at the 8 screw M4.

MAIN SETUP

Connect the VARIAC set at 0VAC from the Mains AC voltage and the power amplifier under test and use a power cord with ground connected.

Turn full anticlockwise the knob of Main Volume.

Set the EQ filter, Low-Mid-High in central position.

Connect the Function Generator to the Line Input(Combo) and set at 1kHz/0.775V.

Connect the Oscilloscope with CH1 probe linked to the Input of the Function Generator and the CH2 probe to the Output of the power amplifier.

Connect a 4 ohm/400W fan load Resistors with an ON/OFF switch and start in OFF position.

DC OFFSET

Switch On the Power Amplifier under test, increase with the VARIAC the AC Voltage slowly and verify in the CH2 the offset stability, reduce

the sensitivity from 20V/div at 5V/div and confirm a maximum offset at +/-0.5VDC.

Switch ON the 4 ohm resistive Load and verify same conditions.

FREQUENCY RESPONSE

Open slowly the Main Volume and verify a perfect 1kHz sinusoidal wave, increase the level until to see a symmetrical square wave.

EQ FILTER

Set the Function Generator at 10dB (0.245V) and test the EQ control.

LOW-EQ control at 100Hz with a range of +/-6dB, Max./Min. of the knob. MID-EQ control at 2kHz with a range of +/-6dB, Max./Min. of the knob. HIGN-EQ control at 10kHz with a range of +/-6dB, Max./Min. of the knob.

MIC GAIN

Set the Function Generator at 10dB(0.245V), connect to MIC input and control the frequency response.

SIG/COMP

Set the knob of the Main Volume at 1/4, set the CH2 at 5V/div, increase the level at 1kHz and check the SIG/COMP LED colour, when the

output is 5V the colour is green. Set the CH2 at 20V/div and increase the level, it must be change from green to red colour, if you increase the input , the output level must keep at same level.

GROUND LIFT

Check the ground-lift with a digital multi-meter, the switch remove the electrical ground Of the input connector (Combo and XLR) form the earth

ground of the chassis.

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