Infinity ENTRA SUB TWO Service Manual page 12

Entra Sub Two
- Voltage measurements
U2(1) U2(14)
306.9mV
2. High Level Input Sensitivity
-Set up
-Voltage measurements 15.3V at speaker output
3. Low-Pass
-Set up
-Voltage measurement
X'OVER FREQ. Setting
4. LFE
-Set up
LFE switch Setting
Normal
See flow chart next page for diagnostics.
U2(8) U3(7)
461mV 460mV 658mV
Turn level, X'OVER FREQ POT Fully CW and LFE switch off
Set Generator at 1.3V@50Hz
Signal to High level input
Set Generator at 200 mV@100Hz
Signal to level input
Line
Measure voltage at S+ speaker output
CW
CCW
Set Generator at 200mV@200Hz
Signal to level input
Line
Measure voltage at S+ speaker output
LFE
OP AMP
U3(1) U3(14) U3(8)
628mV 598mV 2.326V
Output
14.03V
4.8V
Output
6V
18.32V
11
SPEAKER
U5(7) U5(1)
2.02V 3.57V
O/P
23.33V