Infinity 475-A Service manual

Reference Series

475a

4,3,2 CHANNEL POWER AMPLIFIER

SERVICE MANUAL

Infinity Systems, Inc.

250 Crossways Park Dr.

Woodbury, New York 11797 Rev1 3/2008

Released 2007

Discontinued XXXX

475a Reference Series

- CONTENTS -

BASIC SPECIFICATIONS ………………..……….……..1

DETAILED SPECIFICATIONS ………….…..…….……..2

PACKING……………………….……………..……………3

APPLICATIONS……………………………………………4

INSTALLATION/SETUP…………………………...…...…6

BASIC TROUBLESHOOTING..…….…….………………6

EXPLODED VIEW/PARTS LIST………………………....7

NOTE ON TOP COVER…………………………...…...…8

AMPLIFIER BLOCK DIAGRAM……………………..……9

P.C.B. DRAWINGS….…………………………………….10

ELECTRICAL PARTS LIST ……………………………. 16

IC/TRANSISTOR PINOUTS..…………………………….21

SCHEMATICS……………….……..…………..……..…..22

Reference 475a Basic Specifications

Output Power: 75W RMS x 4 @ 4 ohms; ≤1% THD + N

(14.4 VDC) 90W RMS x 4 @ 2 ohms; ≤1% THD + N

Signal-to-noise ratio: 85dBA (reference 1W into 4 ohms)

Dynamic power: 117W channels @ 2 ohms

Effective damping factor: 6.3 @ 4 ohms

Frequency response: 10Hz – 100kHz (-3dB)

Maximum input signal: 6.0V

Maximum sensitivity: 100mV

Output regulation: 0.21dB @ 4 ohms

Dimensions (L x W x D): 14-3/16" x 9" x 2-11/16" (361mm x 229mm x 69mm)

Fuse: 2 x 35A

Infinity continually strives to update and improve existing products, as well as create new ones. The specifications and details in this and related JBL publications are therefore subject to change without notice.

475a Reference Series

INFINITY REFERENCE 475a AMPLIFIER SPECIFICATIONS

TEST VOLTAGE 14.4 +0.1V

Specification Rating Unit Remarks

Power Output 4ohm loads @1kHz (stereo mode) for each ch @<1.0%THD (Unit:W)(LPF=22K)

(stereo mode) for each ch @<1.0%THD (Unit:W)(LPF=22K)

Bridged (Stereo) Mode 4ohm loads @1kHz ≥240W x 2 Watts

≥75W x 4 Watts

≥90W x 4 Watts

Power Output 2ohm loads @1kHz

THD Power 4 ohm loads and 1MD@Reference (Unit:%) LPF=22K

THD Power 2 ohm loads and 1MD@Reference (Unit:%) LPF=22K

THD Power 4 ohm loads Bridged (Stereo) Mode (Unit:%) LPF=22K

Channel Separation @full rated power (+80KHZ) @1kHz

Full rated power Distortion 1KHz LPF=22KHz ≤0.1% %

Signal/Noise Ratio a: 1 watt into 4 ohms b: full rated power (dB)

Input Sensitivity Low Level Input(v) @:full rated power

Frequency response (Unit:-3dB) 10Hz~100kHz Hz -3dB

High-Pass Crossover Frequency limits +20% 40Hz – 450Hz Hz

Low-Pass Crossover Frequency limits +20% 40Hz – 450Hz Hz

Bass Boost:(Unit:dB) @50Hz (±5Hz ) 0~6dB dB ±1dB

≤0.5% @1kHz %

≥45dB

>90

100mV-6V Volts ±20%

dBA

1 watt into 4 ohms

1V signal input

Idle Current ( @ 4ohm) 0.5A A ±0.15A

MAX current : rated power (All channel 2 ohm loads)

DC Offset: ≤30mV mV Damping Factor (4ohm):

Effective damping factor (4ohm): 6.395

Dynamic Power @ 2 ohms 130W Watts Output Regulation @ 4 ohms 0.03dB dB Remote Operating Voltages: ON 5V OFF 4V Volts ±1V Turn on delay time 2 to 3 Sec Circuit Protection a. Temperature b. Speaker Short Circuit c. Operating Voltage Range Dimensions (L x W x H): 14-3/16" x 9" x 2-11/16"

(361mm x 229mm x69mm)

Fuses 35A x 2 A

≤65A A

＞200

95 ±5 deg C

Yes

8~16V

Inches

+0.5V

475a Reference Series

PACKAGING

Item Part Number Description Qty

1 CH4482901203 Outer Carton 1 2 REF475a REF475a Amplifier 1 3 Plastic Bag 1 4 BZL279112001 Packing Foam 1 5 Visit Infinitysystems.com Owner's manual 1 6 Plastic Bag 1 7 Accessory kit consisting of: 1

LS1CJ0402507 Mounting Screws 4 1601-353G-00 SPARE 35A FUSES 2

o Head Unit

Front Output

To Head Unit

Rear Output

Rear SpeakersFront Speakers

To Head Unit Front Output

To Sub Amp

To Head Unit Rear Output

Rear SpeakersFront Speakers

475a Reference Series

APPLICATIONS – 475a

The 475a can be set up for stereo 4-channel, 3-channel or bridged 2-channel operation, as shown in Figures 5 through 8.

NOTE:

• Minimum speaker impedance for stereo operation is 2 ohms. Minimum speaker impedance for bridged operation is 4 ohms.

• Not all possible applications are shown here; e.g., the applications shown in Figures 5, 6 or 8 could include a separate subwoofer driven by an additional amplifier. In that case, the user should refer to Figure 6 for crossover and sub amp connection suggestions.

Figure 5. 475a connected to full-range speakers. Note crossover and channel assignment settings.

Figure 6. 475a connected to four satellite speakers and used in conjunction with an additional subwoofer amplifier or powered subwoofer. Note crossover and channel assignment settings.

To Head Unit Front Output

o Head Unit

ub Output

SubwooferFront Speakers

To Head Unit

Left

To Head Unit

Right

Right SpeakerLeft Speaker

475a Reference Series

APPLICATIONS – 475a

Figure 7. 475a connected in tri-mode to a subwoofer

and a pair of satellite speakers. Note crossover and channel assignment settings.

Figure 8. 475a connected in bridge mode to a pair of full-range speakers. Note crossover and channel assignment settings.

475a Reference Series

INSTALLATION AND SETUP

Refer to the illustrations on the previous pages for control location.

Reconnect the (–) negative lead to the vehicle’s battery. Apply power to the audio system and play a dynamic music track.

SETTING THE CROSSOVER(S)

Determine your system plans and set the crossover-mode switch accordingly. If your system design does not include a subwoofer, set the crossover mode to FULL and skip to “Setting Input Sensitivity.”

If your system includes a subwoofer, set the crossover mode to HP (high-pass) for your full-range speakers. Adjust the crossover frequency to limit bass, and provide increased system volume with less distortion.

Mode Switch:

Full: Allows a full-range signal through to the

speakers; can be used with larger full-range speakers such as 6" x 9"s. HP: Allows a high-pass signal through to the speakers; should be used with most loudspeakers (can protect your full-range speakers from being overdriven with low frequencies, one cause of speaker damage). LP: Allows only bass to pass through to the speakers; should be selected when powering subwoofers.

High-Pass Filters: Initially set the crossoverfrequency control midway. While listening to music, adjust the crossover for the least perceived distortion from the speakers, allowing them to reproduce as much bass as possible.

Low-Pass Filters: For subwoofers, choose the highest frequency that removes vocal information from the sound of the subwoofer.

If using the 475a to drive a subwoofer(s), set the crossover mode to LP (low-pass) on the channels connected to the subwoofer.

NOTE: The 1300a, 1600a and the subwoofer output of the 5350a are low-pass only and do not have a crossover-mode switch.

SETTING INPUT SENSITIVITY

1. Initially turn the INPUT LEVEL control(s) to the minimum (counterclockwise) position.

2. On the source unit, increase the volume control to 3/4 volume. Slowly increase the INPUT LEVEL control(s) toward three o’clock until you hear slight distortion in the music. Then reduce the INPUT LEVEL slightly until distortion is no longer heard.

NOTE: After the source unit is on, blue LEDs (on the top panel) will light, indicating the amplifier is on. If not, check the wiring, especially the remote connection from the source unit. Also refer to “Troubleshooting.”

REMOTE LEVEL CONTROL

The 1300a, 1600a and 5350a include a remote level control. This will allow the subwoofer level to be adjusted from the listening position. Connect the remote level control using the RJ11 jack on the side of the amplifier. Install the control module in the front of the vehicle within easy reach of the driver. Both the underside of the dash and the center console are suitable locations.

UNDER-DASH MOUNTING

Select a mounting location that allows easy access to the control while driving. Using the REMOTE LEVEL control as a template, mark and drill holes in the mounting surface. Attach the REMOTE LEVEL control using the mounting screws provided (Figure 11).

Figure 11. Under-dash mounting of the REMOTE LEVEL control.

Route the cable behind the dash or other interior panels and under the carpet. Do not route the cable outside the vehicle. Connect the RJ11 cable between the RJ11 receptacle on the amp and the receptacle on the REMOTE LEVEL control (Figure 12).

Figure 12. REMOTE LEVEL control electrical connection.

SETTING THE BASS BOOST

The Bass Boost control will allow you to enhance the bass output of your system at 50Hz up to 6dB.

AUX OUTPUT

Reference amplifiers (except 5350a) are equipped with full-range outputs that can be used to connect additional amplifiers.

STATUS LEDs Power: Indicates the amplifier is on. Protection: Refer to “Troubleshooting” for specific

indications.

Figure 13. LED status.

TROUBLESHOOTING

• PROBLEM: No audio (POWER LED is off).

CAUSE and SOLUTION: No voltage at BATT+ and/or REM terminals, or bad or no ground connection. Check voltages at amplifier terminals with VOM.

• PROBLEM: No audio (PROTECT LED glows red).

CAUSE and SOLUTION: DC voltage on amplifier output. Amplifier may need service; see enclosed warranty card for service information.

• PROBLEM: No audio (PROTECT LED glows red).

CAUSE and SOLUTION: Amplifier is overheated. Make sure amplifier cooling is not blocked at mounting location; verify that speaker-system impedance is within specified limits.

• PROBLEM:

No audio (PROTECT LED glows red).

CAUSE and SOLUTION: Voltage less than 9V on BATT+ connection. Check vehicle charging system.

• PROBLEM: No audio (PROTECT LED glows red).

CAUSE and SOLUTION: Voltage greater than 16V or less than 8.5V on BATT+ connection. Check vehicle charging system.

• PROBLEM: Distorted audio.

CAUSE and SOLUTION: Input sensitivity is not set properly, or amplifier or source unit is defective. Check INPUT LEVEL setting, or check speaker wires for shorts or grounds.

• PROBLEM: Distorted audio (PROTECT LED glows

intermittently).

CAUSE and SOLUTION: Short circuit in speaker or wire. Remove speaker leads one at a time to locate shorted speaker or wire, then repair.

• PROBLEM: Music lacks “punch.”

CAUSE and SOLUTION: Speakers are not connected properly. Check speaker connections for proper polarity.

475a Reference Series

Item# Part Number Description Qty

1 SG-0016-2601 Top cover (original, see Page 8) 1

SG-0001-2607 Top cover (Rev1, see Page 8) 1 2 GD-600011400 Light panel 1 3 SR-F475-0117 Main heat sink 1 4 LSIFM0300011 Screw 5 5 Main PCB 1 6 MK-0005-2601 Front panel 1 7 LS5KP0300807 Screw for F/RP 8 8 LS5KJ0301007 Screw for terminal, RCA jacks 6 9 XN-10500-012 Knob 6

10 LSIAP0300607 Screw 6 11 LSIAM0300607 Screw 2 12 XG-0017-2601 Bottom plate 1 13 LSIAY0301201 Screw 2 14 PL-L0007-000 Transistor spring clip (2) 4 15 PL-L0006-000 Transistor spring clip (1) 6 16 ZL-10037A-15 Space Pole 2 17 HG-0006-2601 Rear panel 1 18 LSIAA0200501 Screw 1 19 LS1AM0250401 Screw 4 20 LED PCB 1 21 CP-B00011400 LED lens 1

475a Reference Series

NOTE ON TOP COVER FOR INFINITY REFERENCE MODELS REF475A, REF1300A, REF1600A

• There was a revision in the top cover design starting with the serial number range(s) noted below, or identified by the brace design in the supplied images.

• Note the Rev1 Top cover will not fit properly on the original heatsink.

Top Cover Part Numbers

MODEL PART NUMBER SERIAL NUMBER

EV0001-01000

REF475A

REF1300A

REF1600A

SG-0016-2601

SG-0001-2607

SG-0016-2601

SG-0001-2607

SG-0016-2601

SG-0001-2607

to EV0001-09138 EV0001-09139

And ab ove

EV0003-01000

to EV0003-08606 EV0003-08607

And ab ove

EV0004-01000

to EV0004-11811 EV0004-11812

And ab ove

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