Infinity BU-150 Service manual

BU-150

Powered Subwoofer

SERVICE MANUAL

Infinity Systems Inc.

250 Crossways Park Drive

Woodbury, N.Y. 11797

1-800-553-3332

A Harman International Company

Rev A 3/2000

Amplifier/Subwoofer BU-150

SAFETY INFORMATION

Warning

Any person performing service of this unit will be exposed to hazardous voltages and the risk of electric shock. It is assumed that any person who removes the amplifier from this cabinet has been properly trained in protecting against avoidable injury and shock. Therefore, any service procedures are to be performed by qualified service personal ONLY!

Caution

This unit does not have a power switch. Hazardous voltages are present within the unit whenever it is plugged in.

Before the amplifier is plugged in, be sure its rated voltage corresponds to the voltage of the AC power source to be used. Incorrect voltage could cause damage to the amplifier when the AC power cord is plugged in. Do not exceed rated voltage by more than 10%: operation below 90% of rated voltage will cause poor performance or may shut the unit off.

List of Safety Components Requiring Exact Replacements

F1 Fuse SLO BLO 1.5A 250V 20mm.

UL approved

Leakage/Resistance Check

Before returning the unit to the customer, perform a leakage or resistance test as follows:

Leakage Current. Note there is no power switch on this unit. When the power plug is plugged in, the unit is live. Connect the unit to its rated power source. Using an ammeter, measure the current between the neutral side of the AC supply and chassis ground of the unit under test. if leakage current exceeds 0.5mA, the unit is defective. Reverse the polarity of the AC supply and repeat.

Resistance. Measure the resistance from either side of the line cord to chassis ground. If it is less than 500k ohms, the unit is defective.

WARNING! DO NOT return the unit to the customer if it fails one of these tests until the problem is located and corrected.

PWRCORD SPT-2 or better with polarized plug, UL

approved wired with the hot side to fused side. Use with factory replacement panel strain relief only.

T1 Transformer. Use only factory replacement.

DBR Bridge diode. Use only factory replacement.

C1, 2 2200uF, 100V electrolytic filter caps. Be sure

replacement part is at least the same working voltage and capacitance rating. Also the lead spacing is important. Incorrect spacing may cause premature failure due to internal cabinet pressure and vibration.

C6 4.7uF 100V electrolytic radial

S64AMI Power output module. Use only factory

replacement

Faceplate Faceplate. Use only factory replacement

Air leak cover Use only factory replacement

CMC1 Use only factory replacement

L1 Use only factory replacement

Fuse PCB Use only factory replacement

Main PCB Use only factory replacement

Amplifier/Subwoofer BU-150

TABLE OF CONTENTS

SAFETY INFORMATION..................................................2

GENERAL SPECIFICATIONS..........................................3

DETAILED SPECIFICATIONS .........................................4

CONTROLS AND THEIR FUNCTION .............................6

BU-150 CONNECTIONS .................................................7

OPERATION ...................................................................11

BU-150 TEST SET UP AND PROCEDURE..................12

BU-150 POWER AMP MODULE TESTING

FLOW CHART ................................................................13

BU-150 PACKING & CABINET ASSEMBLY .................14

BU-150 AMPLIFIER ASSEMBLY EXPLODED VIEW....15

BU-150 PCB (Version 3.52) Component Side Trace ....16

BU-150 PCB (Version 3.52) Solder Side Trace ............17

BU-150 PCB (Version 3.53) Component Side Trace ....18

BU-150 PCB (Version 3.53) Solder Side Trace ............19

BU-150 ELECTRICAL PARTS LIST ..............................20

BU-150 INTEGRATED CIRCUIT DIAGRAMS ...............21

BU-150 SCHEMATIC 1 of 2...........................................22

BU-150 SCHEMATIC 2 of 2...........................................23

GENERAL SPECIFICATIONS

Frequency Response (63dB) .................28Hz – 150Hz

Output (RMS).............................200W

Driver ..................................15"Woofer

Crossover Frequency .......................50Hz ~ 150Hz (continuously variable)

Dimensions (HxWxD).....................17) "x17) "x17) " (451 x 451 x 451mm)

Add 1) " (4.5cm) for feet.

Weight..................................55lbs/20 kg

Refinements may be made on occasion to existing products without notice, but will always meet or exceed original specifications unless otherwise stated.

Amplifier/Subwoofer BU-150

DETAILED SPECIFICATIONS

LINE VOLTAGE Yes/NoHi/Lo Line Nom. Unit Notes

US 120vac/60Hz Yes 108-132 120 Vrms Normal Operation

Parameter Spe

cific atio n

Amp Section

Type (Class AB, D, other)

Load Impedance (speaker)

Rated Output Power 200 Watts 120 1 input driven Input voltage 120 VAC, 60 Hz THD 1 % 2 22k filter 120W (Power Bandwidth

THD @ 1 Watt 0.5 % 0.5 22k filter DC Offset <20 mV-DC 30 @ Speaker Outputs Damping factor >80 DF >50 Measured across amplifier

Input Sensitivity

Input Frequency 35 Hz Nominal Freq. 1 input driven Line Input 265 mVrms ±2dB To Rated Power/

Speaker/Hi Level Input 7 Vrms ±2dB To Rated Power/

Signal to Noise

SNR-A-Weighted 100 dBA 90 Relative to rated

SNR-unweighted 75 dBr 70 Relative to rated

SNR rel. 1W-unweighted (22k)

Residual Noise Floor 2 mVrms 3 Volume @max, using RMS reading DMM/VOM (or

Residual Noise Floor 1.5

D n/a Class D Preferred...Sink

8 Ohms n/a Nominal Z-curve required

65 dBr 55 relative to 1W

Unit Test

Limits

mVrms(max)

2 Volume @max, w/ A/P Swept Bandpass

Conditions Notes

required for Class AB

30-100Hz) @ 120 VAC

outputs

1 input driven: AP source Z =

Vol @ Max

output

Output

A/P) , BW <20KHz

Measurement (Line freq.+ harmonics) , BW<20Khz

600 ohms 1 input driven: AP source Z =

25 ohms

A-Weighting filter

22k filter

Input Impedance

Line Input 10K ohms n/a Nominal Speaker/Hi Level Input 5K ohms n/a Nominal

Filters 0dBr = 1w @ 50Hz Low Pass (fixed or

variable) Low Pass filter (point or

range) Slope 24 dB/Octave n/a Q 1 Damping n/a Subsonic filter (HPF) 25 Hz ±2dB -3dB Point Slope 12 dB/Octave n/a Q 1 Damping n/a

Varia ble

60-180Hz ±2dB -3dB Point

Amplifier/Subwoofer BU-150

Limiter (yes/no) yes THD at Max. Output

Power

Features

Phase Switch (yes/no) YES — functional

Volume pot Taper (lin/log)

Input Configuration — Line In (L&R) LR — functional

Spkr/Hi Level In

(L&R) L,R — functional

Spkr Out: Hi Pass Filter 100 Hz functional

Signal-Present LED Yes Signal-Present Input

Freq. Signal-Present Level linein30 mV 35Hz into Line

Signal-Present Speaker

-in

Signal-Present Turn-on time

Auto Mute/ Turn-OFF Time

10 % functional

ck.

Maximum Output Power

Maximum THD as a result of limiting.

45 deg additional phase

ck.

shift/switch op.OK

LOG — functional

ck.

ck..

Enabled w/Line/Spkr

ck..

Input Select Switch

8 ohm Satellite: 6dB/oct passive xover 200 Uf cap. Non polarized

35 Hz Nominal

Zo=600 Ohms Input w/ 1 ch. Driven

2.6 V 35Hz into Speaker Input w/ 1 ch. Driven

1 sec. Amp connected and AC on, then input signal

applied

> 3 min. T before muting,

after signal is removed

Power on Delay time 1 sec. 3 AC Power Applied

Transients/Pops

Signal-Present Transient 5 mV-peak n/a @ Speaker Outputs Turn-on Transient 1 mV-peak 2v-pp @ Speaker Outputs AC Line cycled from OFF to

Turn-off Transient 2 mV-peak 4v-pp @ Speaker Outputs AC Line cycled from ON to

OFF

Efficiency

Stand-by Input Power 20 Watts 28 @ nom. line

Input Line voltage 120 VAC

voltage

Power Cons.@rated power

210 Watts 220 @ nom. line

voltage

Efficiency 95.24%% 54.55% Relative to rated

output

Protection

Short Circuit Protection YES functional

ck..

Thermal Protection YES functional

ck..

Direct short at output

@1/8 max unclipped Power

Power transformer 85 deg C.

Line Fuse Rating 2 Amps 2 Slo-Blo type

Amplifier/Subwoofer BU-150

CONTROLS AND THEIR FUNCTION

1. High-Level input and Output terminals

2. Low-Level Input Jacks: connect to preamplifier outputs

3. Low Pass: This is the crossover frequency control

which determines the upper-corner roll-off points.

4. Power-On indicator

5. Phase: 0/180 switch to change audio-signal polarity.

6. Level: This controls the volume level of the subwoofer.

4 5

SPKR

OUT

SPKR

Line Input

Low

Pass

Phase

180

150

Power

120V 60Hz 250W

BU-150

Level

Min

Digital

RISK OF ELECTRIC SHOCK

TO REDUCE THE RISK OF ELECTRIC SHOCK. DO NOT

EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE

Technology

Powered Subwoofer

CAUTION

DO NOT OPEN

Max

Amplifier/Subwoofer BU-150

BU-150 CONNECTIONS

When connecting your subwoofer make sure you turn all the power off.

There are several ways to connect your subwoofer. Read this section carefully to determine which method is best suited for your installation.

The subwoofer may be fed directly with a low-level signal taken from a preamplifier's output by using the second set of output jacks on the rear of the preamplifier (See Figure 1). If a preamplifier has only one set of outputs, you may use two (2) “Y” connectors (See Figure 2) to connect the subwoofer. Use standard shielded leads terminated at each end with male RCA connectors. Connect one end of each stereo pair of leads to the preamplifier's left and right outputs and connect the other end to the corresponding left and right LOW-LEVEL INPUTS (1) on the subwoofer.

If you are using a tube preamplifier and the connecting leads will be longer than 10 feet (3 meters), we recommend not using the above connection method. A tube preamplifier may not be able to handle the capacitance introduced by leads more than 10 feet in length. Instead, try using the high-level connection methods listed on pages 5-7.

Figure 1.

preamp's output by connecting second set of output jacks to the rear of your amplifier.

Figure 2.

connectors) if your preamp has only one set of outputs.

- A low-level signal can be used from a

- You can use this method (2“Y”

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