46
QSC Audio Products, LLC
PC-003311-00 K-SERIES BOARD - TOP SIDE - REV. D
DATE: JULY 22th, 2010
REV.: B
SHEET 1 OF 3
blue
brown
100 - 260vac
MS-10.250-FU
AC LINE FILTER
XF-000376-00
XF-000376-00
XF-000391-00
PFC-IMPROVING
INDUCTOR
RE-000300-NR
MAIN DC VOLTAGE
RECTIFIER & FILTER CAPACITORS
140VDC@100VAC or 340VDC@230VAC
ACTIVE-CLAMP FLYBACK SUPPLY
HI-CUR. SWITCHING
Q13, Q14, XF-SEC
+/-VCC (+/-85V)
SF-PRI, RECTIFIERS, FILTER
CAPACITORS, AND C124+C52
+R166 (REDUCE SECONDARY
GROUND RIPPLE, EFFECTIVELY
INCREASE SNR)
HOUSEKEEPING VOLTAGES
+15V SUPPLY
-15V SUPPLY
VDD1 (+7V SUPPLY)
+12VLOW SUPPLY
VDD (+12V PSU-BIAS)
MAIN +/-85V RAIL
REGULATION (U3, U6, Q15)
POWER SUPPLY CONTROL CIRCUIT
UNDERVOLTAGE
AC DETECTOR
START-UP - PROVIDING CURRENT
FOR CHARGING C145 THROUGH U15
PWM (U15, U3, T1, T3)
J2A&J2B PINOUTS
1: AGND; 2: CH1; 3: CH2; 4: TEMP; 5: FRONT LED
6: AMP-SD; 7: +7V; 8: PGND; 9: -15V; 10: +15V
J5 PINOUTS
1:
2:
FAN+;
FAN-
J6 PINOUTS
1: +5V; 2: VOL; 3: GND
INPUTS & SIGNAL PROCESSING
SIG. PRE. LED
INPUT A, 2-WAY
LINE IN B
J10, J11,
J12, U14:A
SIGNAL
PRESENCE
LED - INPUT B
2-WAY:
EXT SUB/NORM/DEEP
LF SW
GAIN B
FAN SPEED
CONTROLLER
REMOTE
GAIN
GAIN A
2-WAY
+/-15V_D
FRONT LED
SW
2-WAY: HF SW
VOCAL BOOST/FLAT
STATUS INDICATORS
RED: LIMIT
GREEM: STBY
BLUE: POWER
MIC/LINE SW
2-WAY
CLOCK
EEPROM
DSP
+3.3VD
LINE OUT (U17:A)
(POST GAIN - MIX)
PRE-EMPHASIS (U17:B):
10dB @ 5K HZ
LINE OUTS
(POST DSP)
U19:A = CH1
U19:B = CH2
+1.8VD
LINE IN B
J8, J9,
U14:B
SUB: POLARITY SW
NORMAL/REVERSE
SUB: MODE SW
NORMAL/DEEP
MIC LED, 2-WAY
SELF-OSCILLATING CLASS-D AMPLIFIER
CH2 PWM
U4, F(IDLING) = 400k Hz
TEMP-TO-VOLT
SENSOR U9
CH1 PWM
U2, F(IDLING) = 400k Hz
CH2:
GATE DRIVE U5,
HI-CUR. SWITCHING Q2 & Q3,
OUTPUT FILTER NETWORK L1 & C34
CH2 HF 1ST.
ORDER FILTER
CH2 ZOBEL
NETWORK
CH1 ZOBEL
NETWORK
FRONT
LED
CH1:
GATE DRIVE U7,
HI-CUR. SWITCHING Q4 & Q5,
OUTPUT FILTER NETWORK L2 & C35
11.2 PCB image with notes (all models)
Summary of Contents for K8
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