Infinity INTERMEZZO 2.6 User manual

INTERMEZZO 2.6
POWERED LOUDSPEAKER
SERVICE MANUAL
Infinity Systems, Inc
250 Crossways Park Dr.
Woodbury, New York 797REV5 7/2004

CONTENTS
SPECIFICATIONS …….……………………………………………….3
DETAILED SPECIFICATIONS …………………….…………………4
CONTROLS and CONNECTIONS …………………….….…………6
OPERATION/SYSTEM AURAL SWEEP TEST………..…….……..8
SERVICE BULLETIN INF2000-05 ………….………………….…….9
SERVICE BULLETIN INF2002-04 ….………………….…………...10
TECH TIP INF2003-03………………………………………..………11
MECHANICAL/PACKAGING PARTS LIST…………………………12
EXPLODED VIEW ……………………………………….……………13
PACKAGING …………………………….………………………….…14
WIRING DIAGRAM/HI-PASS CROSSOVER SCHEMATIC…..….15
AMPLIFIER BLOCK DIAGRAM……..…………………….…………16
IM 2.6 ADJUST BIAS PROCEDURE…………….………….………17
ELECTRICAL PARTS LIST (120v)…………………….….…………18
ELECTRICAL PARTS LIST (230v)…………………….….…………26
INTEGRATED CIRCUIT DIAGRAMS ………………………………34
PRINTED CIRCUIT BOARD DIAGRAMS………………..…………35
SCHEMATICS …………………………………………………………39
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Specifications

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Detailed Specifications

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Detailed Specifications (Cont.)

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8
SYSTEM AURAL SWEEP TEST
Equipment needed:
lFunction/signal generator/sweep generator
lIntegrated Amplifier
lMultimeter
lSpeaker cables
General Sweep Function (UUT = Unit Under Test)
1. Turn the RABOS level control on the front of the UUT to “0”. Depress both “High-Pass Filter”
and “Placement” buttons on the rear faceplate.
2. Connect one pair of speaker cables to the input terminals on UUT. Cables should be connected
to an integrated amplifier fed by the signal generator.
3. Turn on signal generator and adjust so that speaker level output at the amplifier is 7.0V, 50 Hz.
4. Plug in and turn on UUT with the power switch; LED on the Level control should light – Red ini-
tially and Green after step #5 is followed.
5. Turn up the RABOS level control on the front of the UUT to “10”. (Maximum). Woofer should be
driving close to maximum excursion at this point.
Driver Function
1. Remove driver from cabinet; (See Page 10), detach + and - wire clips.
2. Check DC resistance of woofer; it should be 3.4 ohms ±10%.
3. Connect a pair of speaker cables to driver terminals. Cables should be connected to an
integrated amplifier fed by a signal generator. Turn on generator and adjust so that speaker level
output is 5.0V.
4. Sweep generator from 20Hz to 1kHz. Listen to driver for any rubbing, buzzing, or other unusual
noises.
The operation of the Intermezzo 2.6 loudspeaker system,and the proper settings for the Room
Adaptive Bass Opitmization System, or R.A.B.O.S., is thoroughly covered in the Owner’s guide, part
#335714-001.
For service purposes, the R.A.B.O.S. system is canceled when all three front panel controls (F) (L)
(W) are turned fully CW, and the Shelf/Stand Placement Selector switch should be set to the
“STAND” position.
The only other control of concern is the Main Level Control on the front panel, which operates like a
traditional potentiometer.
Operation
Left Right

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Service Bulletin
Service Bulletin INF2002-04 - February 2002 Warranty labor rate: MINOR repair
To: All Infinity Service Centers
Model: Intermezzo 2.6
Subject: No Output
In the event you receive an Intermezzo 2.6 loudspeaker with the complaint: “There is no output, and
the LED on the volume control does not light, red or green”, check the items listed below:
Check the 3A line fuse to make sure it’s not open. If open, replace with a 3A MDL (.25 x 1.25) slo-blo fuse,
Infinity part# 80126.
Locate R22 in the power supply section, as shown below.
If value of R22 is not 100k ohms ±5%, then replace R22 with a 1/2 Watt 100k ohm ±5%, resistor.
1) Remove the grille and side panel.
2) Extract (7) of the rubber grille retainers shown in the illustration; this can be accomplished by carefully pulling
them out of their cavities with long-nosed pliers or similar tool.
3) Remove the (7) Phillips screws that are now exposed.
4) Carefully lift the front baffle, with drivers, network, and RABOS controls attached, off the cabinet.
5) Remove the (8) Phillips screws at the rear of the enclosure, and push the amplifier assembly out the front.
6) Locate the power supply section and R22 from the illustrations below. Remove the black plastic guard from
the area of concern (loosen (2) Phillips screws). R22 can be checked in-circuit and should be:
100k ohms ±5%. If it is any other value, or open, replace with Infinity part# RC0082.
7) Replace the guard, the amplifier, reassemble and and test the loudspeaker.
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TECH TIPS
Troubleshooting tips and solutions to common service problems
For models: IL50, IL100s, MSW-1, IL60, IL120s, IM2.6, IM3.5c TIP# INFTT2003-03
Intermezzo, Interlude and Modulus MSW-1 Power Supply Repair
Recommended for instances where the PCB has been damaged, for the above models only:
1) Change all MOSFETS, even for one device failure.
2) Clean and repair the PC board if required (See Tech Tip HCG2002-01 - Damaged Printed Circuit
Boards).
3) Replace the Hybrid Bash Controller IC:
U1 in models: IL50,IL100s,MSW-1,IM2.6,IM3.5c
U501 in models: IL60, IL120s
Infinity part # HC1011
FAILURE TO FOLLOW THE INSTRUCTIONS ABOVE MAY RESULT IN UNIT FAILURE WHEN THE
AMPLIFIER IS POWERED UP
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INTERMEZZO 2.6 L/R MECHANICAL/PACKAGING PARTS LIST
1Cabinet Intermezzo 2.6 L/R (Not for Sale)
2Grille (R/L) (Pair) Blue 335453-050
(R/L) (Pair) Gray 335453-040
(R/L) (Pair) Burgundy 335453-060
3Side Trim Panels (R/L) (Pair) (Black) 335452-030
(R/L) (Pair) (Cherry) 335452-020
(R/L) (Pair) (Maple) 335452-010
4Front Baffle (R) 335277-001
(L) 335277-002
5Low Frequency Transducer
6 ½” (165mm) C.M.M.D.
Neodymium, shielded
DC Resistance 3.3 ohms ±10%
IM165GS
6High Frequency Transducer
1” (25mm) C.M.M.D.
Neodymium, Shielded
DC Resistance 3.4 ohms ±10%
335225-002
7Mid/Twt Crossover Network (L) 335458-002
8Amp assembly Not for Sale
9Rabos Control Assembly (R) 335457-001
10 Grille retainers (11) 333249-003
11 Woofer Protector Ring 336219-001
12 Rear Base Gasket 331106-001
13 Rubber feet (4) 335459-001
14 Power cord WI0032
15 Outer Carton 335736-001
16 Top Foam Pad 335737-001
17 Bottom Foam Pad 335737-002
18 Owner’s manual 335714-001
19 Warranty Card 335841-001
20 Survey Card 335868-002
21 RABOS Complete kit 335852-001
22 RABOS Test CD 335855-001
23 RABOS Sound Level Meter 335368-001
24 RABOS Key (Screwdriver) 091-00121-000
25 RABOS Q-Finder 335856-001
26 RABOS Pouch 335853-001
27 9 Volt Battery Not for Sale
28 Screw (tweeter) (4) PPH 6-32 x 3/8” ZNC 10811
29 Screw (front baffle) (7) PPH 8-32 x 2 ¼” ZNC 900202-036
30 Screw (woofer) (4) FPH 8-32 x .5 ZNC 901702-008
31 Screw (amplifier) (8) PPH 6-32 x .5” BLK 900301-008
32 Screw (network) (6) PPH 6-32 x 3/8” ZNC 10811
33 Screw (RABOS Controls) (4) PPH 6-32 x .5” BLK 900301-008
34 Screw for Stand/Wall Mt. Bracket (8) PPH ¼ x 20 BLK 900501-008
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Exploded View
13
Remove and discard when woofer is replaced with part# IM165GS

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ackaging
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Wiring Diagram
Intermezzo 2.6 Hi- ass Schematic
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Amplifier Block Diagram
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IM 2.6 ADJUST BIAS PROCEDURE
(Mandatory when any output MOSFET transistors Q3,4,7,8 are replaced)
1. Amplifier should be unplugged and OFF.
2. Remove Amp assemblyfrom cabinet, following the instructions on Page 11. Allwires can
remain connected unless they will prevent you from removing the amplifier or accessing
potentiometers on the Linear board PCB in the following steps.
3. Locate the Linear board assembly (PCB with the output transistors)
4. Adjust R11 and R27 fully Counter Clockwise. See diagram below.
5. Apply 120 VAC power to unit, Turn power switch ON.
6. Verify LED illuminates on the front gain control dial unless you have disconnected the plug.
7. Remove shorting plug on terminal J7 on Linear board, and insert current meter, set to the
low mA range.
8. Verify initial current is less then 1 mA.
9. Adjust R11 Clockwise until current meter reads 5 mA + the initial current from step #8.
10.Adjust R27 Clockwise until current meter now reads 10 mA + the initial current from step #8.
11.Turn amplifier OFF. Disconnect AC power to unit.
12.Remove current meter; insert shorting plug back in terminal J7.
13.Replace cover (if present), wires if disconnected, and replace amplifier back into cabinet.
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Electrical Parts List (120V)
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Electrical arts List (120V) (Cont.)
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Electrical arts List (120V) (Cont.)
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Change R22 
to 100K ohm 
- See Page 10