Infinity Interlude Series, Service Manual

Page: 15 / 37

IL120s
15
TEST SETUP and PROCEDURE
0
0516
SIGNAL
GENERATOR
AMPLIFIER
AC VOLT
METER (10V)
IL120s
UNDER TEST
OUTPUT
FROM
GENERATOR/AMPLIFIER
0
0345
®
®
O
R
SYSTEM AURAL SWEEP TEST
Equipment needed:
• Function/signal generator/sweep generator
• Integrated Amplifier
• Multimeter
• Speaker cables
General Unit Function (UUT = Unit Under Test)
Switches/knobs on the amplifier faceplate:
Input Select to “Line”
Low Pass Filter to OFF
Bass Optimization system to OFF
Low Pass Frequency Adjust full CW (150Hz)
Phase switch – either position
1. From the signal generator, Connect both right and left line level inputs (RCA) to signal generator and UUT. Use Y-cable if
necessary from mono source.
2. On the front of the unit, turn the LEVEL control full clockwise (0).
3. Turn on generator, adjust to 120mV, 30 Hz.
4. Plug in UUT; turn the power switch ON. LED should be Red. Turn LEVEL control full counterclockwise (10)
5. LED should now be Green; immediate bass response should be heard and felt from rear port tube opening.
6. Turn off generator, turn LEVEL control fully clockwise (0), disconnect RCA cable.
7. Connect one pair of speaker cables to Speaker Level input terminal on UUT. Cables should be connected to an integrated
amplifier fed by the signal generator.
8. Switch Input to “Speaker”.
9. Turn on generator and adjust so that speaker level input at the amplifier is 2.2V, 30 Hz. Turn LEVEL control full counter-
clockwise (10)
10. Green LED should light, immediate bass response should be heard and felt from the port tube opening.
Sweep Function
1.
Follow steps 7-10 above, using a sweep generator as a signal source.
2. Sweep generator from 20Hz to 20kHz. Listen to the cabinet and drivers for any rattles, clicks, buzzes or any other noises. If
any unusual noises are heard, remove woofer and test.
Driver Function (Woofer)
1.
Remove woofer from cabinet; and - wire clips. See page 12 for removal instructions.
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.