Alto X-P234 Schematic
Service Manual
Model: X-P234 (2,3-WAY STEREO 4-WAY MONO )
ACTIVE CROSSOVER
www.altoproaudio.com
Version: 1.1
CONTENTS
1. Specification
2. Block Diagram
3. Schematic Diagram
4. Printed Circuit Board
5. Wiring Diagram
6. Test Procedure
7. Electrical Parts List
8. Exploded Views & Mechanical Parts List
9. Notes
INPUT
1. SPECIFICATION (X-P234)
Connectors
Type
Impedance
Max. Input Level
CMRR
OUTPUT
Connectors
Type
Impedance
Max. Output Level
PERFORMANCE
Bandwidth
Frequency Response
Signal to Noise
Low Output
Low-Mid Output
Mid Output
High-Mid Output
High Output
Dynamic Range
THD& Noise
Interchannel Crosstalk
XLR
Electronically servo-balanced, RF filtered
Balanced >50K Ohms, unbalanced >25K Ohms
+22dBu typical, balanced or unbalanced
>40dB, typically > 55 dB at 1 KHz
XLR
Electronically servo-balanced, RF filtered
Balanced 60 Ohms, unbalanced 30 Ohms
+20dBu balanced or unbalanced
20Hz to 20KHz, +0/-0.5dB
<5Hz to>90KHz, +0/-3dB
Ref: +4dBu, 20Hz to20KHz,unweighted
Stereo Mode:
>93dBu
>95dBu
>90dBu
>106dB,unweighted
Limiter Off
<0.04%
High to Low:
High to Mid:
Mid to Low:
High to High-Mid:
High-Mid to Low-Mid:
Low-Mid to Low:
>93dBu
>94dBu
>94dBu
>88dBu
Limiter On
<0.5 %
<93dBu
<94dBu
<95dBu
<95dBu
<95dBu
<92dBu
Mode:Mono
CROSSOVER
Filter Type
Stereo Mode Frequencies
Low/High
Low/Mid
Mid /High
Mono Mode Frequencies
Low/Low-Mid
Low-Mid/High-Mid
High-Mid/High
FUNCTION SWITCHES
Front Panel
Low Cut
Mute
Phase Invert
CD Horn
Limiter
Rear Panel
Xover Frequency
Mode
LF Sum
Linkwitz-Riley, 24dB/Octave, state-variable
1
44Hz to 930Hz
44Hz to 930Hz
440Hz to 9.3KHz
1
44Hz to 930Hz
440Hz to 9.3KHz
440Hz to 9.3KHz
Activates 25 Hz Butterworth, 12 dB/Octave high-pass filter
Mutes the individual output
Inverts the phase at the individual output
Corrects CD horn frequency response above 3.5KHz
Activates the limiter function for all outputs
Mutiplies crossover frequency range by 10
Selects stereo /mono and 2/3/4-way operation
Selects normal stereo or mono-summed low frequency operation
ON=Channel1+6dB Louder Channal2: the same as before
10
440Hz to 9.3KHz
440Hz to 9.3KHz
10
440Hz to 9.3KHz
,
CONTROLS
Input
Xover Frequency
Delay
Gain
Threshold
POWER SUPPLY
Connector type
Type
Mains supply
Power Rating
Fuse
PHYSICAL
Dimensions
Net Weight
Controls the input gain(+/-12dB)
Controls the crossover frequency
Controls the delay at the low output(0 to 2 msec.)
Controls the output gain(+/-6dB)
Controls the threshold of the limiter (-6dB to OFF)
3-pole IEC, grounded
serve controlled, stabilized
95-120V /210-240V ,60-50Hz
<17W
210-240V: T250mAL 250VAC
95-120V: 500mA 250VAC
483(W)
194.5(D) 44(H)mm(19" 7.7" 1.7")
3.3Kg(7.27lb)
D
2.Block Diagram
87654321
A-CHANNEL
LOW OUTPUT
213
A-CHANNEL
MID OUTPUT
213
A-CHANNEL
HIGH OUTPUT
213
C
B-CHANNEL
LOW OUTPUT
213
B-CHANNEL
MID OUTPUT
213
B
B-CHANNEL
HIGH OUTPUT
213
A
SCX-P234 BLOCK DIGRAM
11 of
TASY J.S.
RevisionModel No:
Drawn By:
Sheet
SCX-P234 V1.0
2-Nov-2002
P234 BLOCK DIGRAM.Sch
A4
Titel
Size
File:
Date:
ON / OFF
MUTE
LIMITER
DELAY
PHASE
LOW GAIN
MUTE
LIMITER
PHASE
MID GAIN
XOVER
FREQ. x1 OR x10
MUTE
LIMITER
PHASE CD HORN
HIGH GAIN
MUTE
LIMITER
DELAY
PHASE
LOW GAIN
OFFON
OFF
ONOFF
ON
-----
-----
-----
-----
MUTE
LIMITER
PHASE
MID GAIN
XOVER
FREQ. x1 OR x10
MUTE
LIMITER
PHASE CD HORN
HIGH GAIN
440 Hz TO 9.3 KHz
440 Hz TO 9.3 KHz 44 Hz TO 930 Hz
440 Hz TO 9.3 KHz
x1 x10
STEREO MODES FREQUENCIES
x1 x10
44 Hz TO 930 Hz
440 Hz TO 9.3 KHz
MID / HIGH
(2-WAY) LOW / HIGH
(3-WAY) LOW / MID
MONO MODES FREQUENCIES
44 Hz TO 930 Hz
(4-WAY) LOW / LOW-MID
440 Hz TO 9.3 KHz
440 Hz TO 9.3 KHz
LOW-MID / MID-HIGH
MID-HIGH / HIGH
MODE
2-WAY STEREO-----
3-WAY STEREO
4-WAY MONO
NOT VALID
-----
-----
-----
LOW CUT GAIN
213
INPUT
A -CHANNEL SIGNAL
D
ON
OFF
C
LOW CUT GAIN
213
INPUT
B -CHANNEL SIGNAL
1 2 3 4 5 6 7 8
B
A
87654321
3. Schematic Diagram
TO CN2-16
CN2
24PIN
24
23
22
21
CN1
20PIN
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
D
C
B
A
1 2 3 4 5 6 7 8
HI
TO CN2-22
TO CN2-20
LO
TO CN2-10
TO CN1-2
LOW CUT
TO CN2-23
TO CN1-19
TO CN2-18
MID
TO CN1-1
R123
10K
R120
10K
C3
47uF
C23
47UF/25V
R119
VR1
50KB
C4
47UF/25V
10K
12
13
R27
15K
R26
15k
R118
10K
2
3
VR5
10KB
R24
3K22
IC10D
TL074
R29
47P
VR4
10KB
R23
3K22
14
IC4A
2068
C5
47uF
VR3
10KB
R50
15K
R51
4K99
SW6
INV
SW2
R28
20K
R30
20K
SW4
INV
INV
C1
47uF
SW1
LOW CUT
R40
15K
R38
4K99
47uF
R71
3K32
1
C2
R39
15K
R37
4K99
9
10
C48
150N
6
5
R48
10K
R42
10K
C56
20P
R46
30K1
2
3
R41
10K
6
5
IC5C
TL074
R33
60K4
C52
20P
R44
30K1
IC5B
TL074
C51
20P
30K1
IC4B
2068
C49
150N
R52
2K21
R47
2K21
R43
IC5A
TL074
R34
30K1
8
7
R108
180R
1
VR2A
100KB
VR2B
100KB
7
C13
47uF
C84
15N
R182
18K2
R181
2K21
R55
511R
R57
511R
R89
10K
Q9
2N7002
-15V
C85
4N7
R107
47K5
R109
2K67
IC10B
TL074
6
5
+15V
VR11
10KB
R60
10K
C58
5N6
C57
5N6
R91
68R
6
5
1
-15V
7
C24
47uF
SW16
LIMITER
37K4
IC6A
2068
C16
220uF
R90
560K
R93
6K34
R22
10M
R59
C14
10uF
IC6B
2068
3
2
BAS16
5
6
13
12
2
3
D4
C80
100P
CD HORN
R49
2K21
7
2
3
IC8B
2068
R92
560K
SW8
IC8A
2068
R86
10K
R88
5K11
R87
100K
C55
100P
R45
2K21
IC5D
TL074
IC10A
TL074
C6
47uF
R58
27K4
R56
10K
1
7
14
1
LIMITER
C15
47uF
BAS16
CD HORN2
CD HORN1
R98
10K
C18
47uF
Q9
2N7002
R64
10K
Q5
2N7002
R95
47K5
R94
10K
D3
Q8
BR
R101
68R
R74
68R
-15V
-15V
LED9
10M
SW5
MUTE
RD
R103
560K
R104
6K34
R100
10M
R76
560K
R80
6K34
R21
R6
1K5
C21
220uF
C10
220uF
+15V
C19
4.7uF
C7
22uF
4.7uF
3
2
BAS16
5
6
3
2
BAS16
5
6
C17
C20
IC9A
47uF
2068
1
R96
10K
C81
100P
D6
7
IC9B
2068
R102
560K
R99
5K11
R97
100K
IC7A
2068
1
R62
10K
C61
100P
D2
IC7B
2068
7
R75
560K
R65
5K11
R63
100K
BAS16
C8
47uF
BAS16
Titel
Size
Date:
File:
D5
D1
R106
47K5
R105
10K
R85
47K5
R84
10K
P234FP-1(CH1)
A3
SW7
MUTE
+15V
LED11
RD
Q10
BR
SW3
MUTE
+15V
LED7
RD
R4
1K5
Q6
BR
X-P234
7-Jun-2002
P234FP-1.SCH
R17
1K5
C22
4.7uF
C12
4.7uF
Sheet
Drawn By:
RevisionModel No:
TASY J.S.
D
C
B
A
V1.0
31 of
87654321
TO CN2-4
CN2
24PIN
24
23
22
21
CN3
20PIN
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
D
C
B
A
1 2 3 4 5 6 7 8
HI
TO CN2-12
TO CN2-8
LO
TO CN2-9
TO CN3-2
LOW CUT
TO CN2-14
TO CN3-1
TO CN2-6
MID
TO CN3-20
C28
47uF
C29
47UF/25V
VR6
50KB
C30
47UF/25V
R112
15K
R113
15k
R137
15K
VR10
10KB
SW14
R154
3K22
C31
47uF
VR8
10KB
R115
47P
2
3
IC11A
2068
VR9
10KB
R162
3K22
INV
R25
3K32
R111
20K
1
R116
20K
SW12
INV
SW11
INV
R139
4K99
C26
47uF
SW9
LOW CUT
R127
15K
R125
4K99
47uF
C27
R126
15K
R124
4K99
9
10
C89
150N
6
5
C97
20P
R133
30K1
R135
10K
R129
10K
2
3
6
5
R128
10K
IC12C
TL074
R121
60K4
C93
20P
R131
30K1
IC12B
TL074
C92
20P
R130
30K1
IC12A
TL074
30K1
IC11B
2068
C191
150N
8
R138
2K21
R134
2K21
R122
7
R117
180R
1
VR7A
100KB
VR7B
100KB
7
C37
47uF
C88
15N
R140
511R
R142
511R
R160
10K
Q13
2N7002
C86
4N7
R110
8
IC13A
2068
220uF
R164
560K
C25
47uF
R144
37K4
C40
C38
10uF
47K5
IC13B
2068
3
2
BAS16
5
6
13
12
C103
100P
D10
CD HORN1
CD HORN2
R136
2K21
100P
LIMITER
7
2
3
IC15A
2068
R158
10K
IC15B
2068
R166
560K
R161
5K11
R159
100K
C96
R132
2K21
IC12D
TL074
C32
47uF
R143
27K4
R141
10K
R173
10K
R175
R148
10K
R169
47K5
Q14
BR
68R
R152
68R
-15V
-15V
LED20
RD
10M
SW13
MUTE
C42
47uF
14
Q15
2N7002
Q11
2N7002
1
C39
47uF
7
R168
10K
D9
BAS16
IC?C
R114
TL074
2K67
10
9
R145
10K
C99
5N6
C98
5N6
R165
68R
-15V
6
5
1
R167
6K34
R163
10M
R177
560K
R178
6K34
R174
10M
R151
560K
R155
6K34
R150
R19
1K5
C45
220uF
C35
220uF
+15V
C43
4.7uF
C33
22uF
4.7uF
3
2
BAS16
5
6
3
2
BAS16
5
6
C41
D8
D12
R176
560K
IC16B
2068
IC14A
2068
R146
10K
R153
560K
IC16A
2068
R170
10K
C104
100P
R171
100K
C100
100P
IC14B
2068
R149
5K11
R147
100K
1
7
R172
5K11
1
7
C44
47uF
C34
47uF
BAS16
BAS16
Titel
Size
Date:
File:
R180
47K5
R179
10K
D11
R157
47K5
R156
10K
D7
P234FP-2(CH2)
A3
SW15
MUTE
+15V
LED22
RD
Q16
BR
SW10
MUTE
+15V
LED8
RD
R18
1K5
Q12
BR
X-P234
7-Jun-2002
P234FP-2.SCH
R20
1K5
C46
4.7uF
C36
4.7uF
Sheet
Drawn By:
RevisionModel No:
TASY J.S.
D
C
B
A
V1.0
32 of
4321
-15V +15V
LED13
TO CN2-3
D
CN2
24PIN
24
23
22
21
20
19
18
17
16
15
C
14
13
12
11
10
9
8
7
6
5
4
3
2
1
+15V
TO CN2-5
TO CN2-17
TO CN2-19
TO CN2-1
TO CN2-2
TO CN2-11
TO CN2-21
TO CN2-24
TO CN2-13
TO CN2-15
TO CN2-7
-15V
+15V
R35
15K
R36
39K2
Q2
HR
LED19
GN
LED17
GN
R2
470R
LED1
GN
LED15
GN
LED16
GN
YE
LED2
YE
LED21
GN
LED6
GN
LED5
GN
LED3
GN
LED8
GN
LED14
GN
R54
15K
R53
39K2
LED4
GN
Q3
HR
R5
470R
LED12
GN
R61
15K
R66
39K2
LED10
GN
Q4
HR
+15V
R3
470R
CN3
20PIN
20
19
18
17
16
15
14
13
12
11
10
D
TO CN3-9
TO CN3-3
TO CN3-10
TO CN3-4
TO CN3-7
TO CN3-5
TO CN3-8
TO CN3-6
TO CN3-17
9
8
7
6
5
4
3
2
1
TO CN3-11
TO CN3-18
TO CN3-12
TO CN3-15
TO CN3-13
TO CN3-16
TO CN3-14
VR14A
C50K
VR14B
C50K
VR14C
C50K
VR14D
C50K
VR15A
C50K
VR15B
C50K
VR15C
C50K
VR15D
C50K
CN1
20PIN
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
TO CN1-12
TO CN1-18
TO CN1-11
TO CN1-17
TO CN1-14
TO CN1-16
TO CN1-13
TO CN1-15
TO CN1-4
TO CN1-10
TO CN1-3
TO CN1-9
TO CN1-6
TO CN1-8
TO CN1-5
TO CN1-7
VR12A
C50K
VR12B
C50K
VR12C
C50K
VR12D
C50K
C
VR13A
C50K
VR13B
C50K
VR13C
C50K
VR13D
C50K
B
-15V
+15V
A
-15V
C50
104P
C47
104P
C90
104P
C87
104P
1 2 3 4
84
IC4C
2068
84
IC11C
2068
C53
104P
C54
104P
C94
104P
C95
104P
411
IC5E
TL074
411
IC12E
TL074
C73
104P
C71
104P
C102
104P
C101
104P
84
IC6C
2068
84
IC13C
2068
84
IC7C
2068
84
IC14C
2068
84
IC8C
2068
84
IC15C
2068
C83
104P
C82
104P
84
IC9C
2068
84
IC16C
2068
411
IC10E
TL074
Titel
Size
Date:
File:
P234FP-3
A3
X-P234
7-Jun-2002
P234FP-3.SCH
Sheet
Drawn By:
RevisionModel No:
V1.0
33 of
TASY J.S.
B
A
87654321
D
C
B
X3
CHANNEL1
X7
CHANNEL2
CN2
2
4
6
8
10
12
14
16
18
20
22
24
1
2
3
4
1
2
3
4
TO CN3-6
TO CN3-14
TO CN1-18 TO C7
SW4
MODE
+15V
-15V
R3
13K3
R34
13K3
R53
13K3
R52
13K3
-15V
C98
47P
R43
13K3
R44
13K3
C97
47P
C33
47P
13K3
C32
47P
TO CN1-10
-15V
R51
R50
13K3
SW3
MODE
2
3
6
5
C29
47P
R46
26K1
R45
26K1
C28
47P
C30
47P
R48
26K1
C31
47P
+
-
+
-15V
-15V
IC9B
2068
R49
26K1
IC9A
2068
1
7
TO CN2-2
TO CN2-11
SW2
LF SUM
-15V
CN2
23
21
19
17
15
13
11
9
7
5
3
1
TO CN2-17
TO CN2-19
TO CN2-21
C12
47UF/25V
C13
47UF/25V
C14
47UF/25V
R54
10K
R67
10K
R80
10K
R64
10K
R58
3K16
R62
2K67
R77
10K
R71
3K16
R75
2K67
R90
10K
R85
3K16
R89
2K67
2
3
5
6
2
3
5
6
2
3
5
6
C36
47P
R65 5K76
-
+
R61
R60 3K24
R59 4K53
+
R55
C39
47P
R78 5K76
-
+
R74 4K53
R73 3K24
R72 4K53
+
-
R68 6K04
C43
47P
R91
5K76
-
+
R87 4K53
R86 3K24
R83
5K76
+
-
R81
6K04
IC13A
2068
4K53
IC13B
2068
6K04
IC14A
2068
IC14B
2068
IC15A
2068
IC15B
2068
C18
2
3
5
6
2
3
5
6
2
3
5
6
47P
R15 5K76
-
+
R11
R10 3K24
4K53
R9
+
R5
C21
47P
R28 5K76
-
+
R24 4K53
R23 3K24
R22 4K53
+
-
R18 6K04
C25
47P
R41
5K76
-
+
R37 4K53
R36 3K24
R35
5K76
+
-
R31
6K04
IC10A
2068
4K53
IC10B
2068
6K04
IC11A
2068
IC11B
2068
IC12A
2068
IC12B
2068
R13
1
7
1
7
1
7
60R4
R16
3K16
R6
60R4
R26
60R4
R29
3K16
R19
60R4
R39
60R4
R42
3K16
R32
60R4
TO X4-3
C19
470P
TO X4-2
C99
470P
TO X5-3
C22
470P
TO X5-2
C20
470P
TO X6-3
C46
470P
TO X6-2
C45
470P
4
3
2
1
X4
LOW OUTPUT
4
3
2
1
X5
MID OUTPUT
4
3
2
1
X6
HIGH OUTPUT
D
C
B
R14
R4
10K
R17
10K
R30
10K
10K
R8
3K16
R12
2K67
R27
10K
R21
3K16
R25
2K67
R42
10K
R33
3K16
R38
2K67
CHANNEL 2 CHANNEL 1
R63
1
7
1
7
1
7
60R4
R66
3K16
R56
60R4
R76
60R4
R79
3K16
R69
60R4
R88
60R4
R92
3K16
R82
60R4
TO X8-3
C38
470P
TO X8-2
C37
470P
TO X9-3
C44
470P
TO X9-2
C41
470P
TO X10-3
C46
470P
TO X10-2
C45
470P
4
3
2
1
X8
LO OUTPUT
4
3
2
1
X9
MID OUTPUT
4
3
2
1
X10
HIGH OUTPUT
C9
47UF/25V
TO CN2-5
C10
47UF/25V
TO CN2-7
C11
47UF/25V
TO CN2-9
+15V
A
-15V
1 2 3 4 5 6 7 8
84
IC9C
2068
84
IC10C
2068
C47
104P
C17
104P
84
IC11C
2068
84
IC12C
2068
C23
104P
C24
104P
84
IC13C
2068
C34
104P
C35
104P
84
IC14C
2068
84
IC15C
2068
C40
104P
C42
104P
Titel
Size
Date:
File:
P234PU-1
A3
X-P234
7-Jun-2002
P234PU-1.SCH
Sheet
Drawn By:
RevisionModel No:
TASY J.S.
A
V1.0
21 of
Loading...