ez1073-500 Lunchbox Mic/Line EQ - Assembly manual
[“Colourbook” Issue 1g]
Ez1073-500 “Colourbook” Contents.
Section 1 - “Colourbook” assembly guide
Section 2 - Schematics diagrams and PCB Overlays
Section 3 - Parts List
Section 4 - Setup and Calibration
Ez1073-500 “Colourbook” revision history
Revisions 1 to 1a;
Minor corrections and additions
Revisions 1a to 1b;
Faceplate fitting and heatsink clarification
Revisions 1b to 1c;
Output link cable drawing
Schematics and overlays added
Test/Calibration procedure added
Revisions 1c to 1d;
Output transistor heatsink change
AP Plots added
Revisions 1d to 1e;
Shakeproof washer missing from heatsink screw
Revisions 1e to 1f;
Output transistor orientation clarification
R143 and C89 description clarification
Revisions 1f to 1g;
Warning added about length of pins on
switch card / clash with R2, R3 & R4
Calibration procedure “R49 alternative method” added
for setting bias.
Output Termination
Place a “blob” of solder across the two pads for 600 Ohm termination
300
1200
LoZ
Caution HOT!
48v
Mic/Line
EQ In
O/P Phase
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
HF
Gain
MF
Gain
MF
Freq
LF
Gain
LF
Freq
VTB9050
VTB9044
Caution - HOT!
Components
may become
hot during use
Output Link
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Opamp B
Opamp A
Option
Hot
Cold
Line Output
Diodes
D1, D2, D3 = 1N4001 or 1N4007 (3)
Caution HOT!
300
1200
LoZ
Mic/Line
48v
EQ In
O/P Phase
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
HF
Gain
MF
Gain
MF
Freq
LF
Gain
LF
Freq
VTB9050
VTB9044
Caution - HOT!
Components
may become
hot during use
Output Link
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Opamp B
Opamp A
Option
Hot
Cold
Line Output
Resistors
R50 = 0R (1)
R49 = 1R0 (1)
R15 = 5R6 (1)
R14, R16, R56 = 10R (3)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R46 = 12R (1)
R13 = 15R (1)
R12 = 22R (1)
R11 = 39R (1)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R10 = 56R (1)
R39 = 82R (1)
R9 = 91R (1)
R98 = 120R (1)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R2 = 130R (1)
R8 = 150R (1)
R111 = 220R (1)
R7 = 240R (1)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R42 = 270R (1)
R3, R6 = 360R (2)
R122, R134 = 390R (2)
R118,R130 = 470R (2)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R29 = 510R (1)
R43, R61, R62 = 620R (3)
R102, R107 = 820R (2)
R28 = 1k0 (1)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R25, R144 = 1k2 (2)
R44, R119, R131 = 1k5 (3)
R27, R121, R133 = 1k8 (3)
R142 = 2k0 (1)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R34, R47, R123, R135, R138 = 2k2 (5)
R30, R31, R84, R112 = 2k7 (4)
R1, R35, R89, R92 = 3k3 (4)
R103, R108 = 3k6 (2)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R5, R26, R36, R100, R105 = 3k9 (5)
R37 = 4k3 (1)
R48, R117, R129 = 5k1 (3)
R55 = 5k6 (1)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R60, R78, R81, R82 = 6k8 (4)
R83 = 8k2 (1)
R41, R52, R99, R104, R124, R136 = 10k (6)
R33, R63, R79 = 12k (3)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R38 = 15k (1)
R32, R40, R140 = 18k (3)
R54 = 22k (1)
R87, R90 = 27k (2)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R113, R125, R139 = 33k (3)
R4, R45, R80, R88, R91 = 39k (5)
R114, R126 = 47k (2)
R120, R132 = 51k (2)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R141 = 56k (1)
R115, R127, R137 = 68k (3)
R51, R86, R93 = 100k (3)
R95, R96, R116, R128 = 120k (4)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R94, R97, R101, R106 = 180k (4)
R85 = 220k (1)
R53 = 1M0 (1)
R17-R24, R64-R77 = 4M7 (22)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Resistors
R146 = 47R / 3Watt (1) - (Mount on rear side of PCB)
R109, R110 = 6k81 - 0.1% (2)
The actual value of R109 and R110 is less important than their closeness of matching.
2 accurately matched 1% resistors are better than 2 inaccurately matched 0.1% resistors
R143 = Omitted (leave empty) (1)
Mount on rear
side of PCB
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Ceramic
C49, C51 = 47pF (2)
Capacitors
C66, C76 = 100pF (2)
C7, C41 = 180pF (2)
C88 = 220pF (1)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Ceramic
C87 = 330pF (1)
Capacitors
C50, C52, C53 = 470pF (3)
C47, C48 = 680pF (2)
C21 = 100nF (1)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Film
C42 = 220pF (1)
Capacitors
C63, C73 = 680pF (2)
C57, C58, C72, C82 = 1nF (4)
C67, C77 = 1n5F (2)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Film
C18, C27, C30 = 2n2F (3)
Capacitors
C28, C86 = 4n7F (2)
C14, C29, C44 = 10nF (3)
C24, C25, C34 = 15nF (3)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Film
C3, C10, C22, C23, C31 = 22nF (5)
Capacitors
C26, C32, C38 = 47nF (3)
C2, C9, C16, C33, C35, C36, C37, C39, C40, C45 = 100nF (10)
C1, C8 = 220nF (2)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Film
C15 = 330nF (1)
Capacitors
C5, C12 = 470nF (2)
C6, C17, = 1uF (2)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Electrolytic
C43, C46, C64, C74, C85 = 10uF / 50v (5)
All positive terminals towards left
Capacitors
Fit C13 like this
else it will touch the
rear of the stage 2
subcard.
C4, C13, C56, C59, C60, C61, C65, C69, C70, C75, C79, C80 = 22uF / 63v (12)
C54, C55, C68, C78, C83, C84, C90 = 100uF / 25v (7)
C71, C81 = 470uF / 16v (2)
C89 = Omitted (Leave empty) (1)
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Small Signal Transistors
(All “flat side
to the left”)
Q2, Q3 = BC560C (2)
Q4-Q17 = BC184C (14)
R145 = 4K7 (or 5k) (1) - Side adjust style
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Electrolytic
Capacitors
C11, C19, C20, C62 = 470uF / 35v (4) All positive terminals towards left
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Voltage Regulator
U1 = 7808 voltage regulator (1)
M3 nut
Insulating bush
Insulating washer/sheet
PCB
M3 Nylon Washer
M3x10 screw
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Output Transistor
TIP3055
Insulating washer/sheet
Heatsink
6-32 UNC screw
M3 Shakeproof Washer
Metal side
Bend legs like this.
M3 Plain Nut
M3 Shakeproof Washer
M3 x 35mm screw
M3 Plain Nut
M3 Shakeproof Washer
M3 Plain Washer
M3 Plain Washer
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Line Output
Inductors
IN1 = VTB9043
IN1 = VTB9050
IN1 = VTB9044
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Rotary Switches
SW3 = GR-03-001 (1) - 12 position, 1 pole, 3 gang
SW1, SW5 = GR-03-002 (2) - 12 position, 1 pole, 1 gang
SW2, SW6 = GR-03-003 (2) - 6 position, 2 pole, 1 gang
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Potentiometers
R57, R58 = OM-01-082 (2) - 10k Linear 20mm
R59 = OM-01-083 (1) - 47k Linear 20mm
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Toggle Switches
SW7, SW8, SW9, SW10, SW11 = 2 Position DPDT (on-on) (5)
Make absolutely certain they stand
perpendicular to the PCB !
Use the faceplate as a guide before
soldering them completely.
300
1200
LoZ
48v
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Ribbon Cable
J6 = 16 Way Box Header (1)
J1 = 16 Way Ribbon/Transition Header (1)
Pin 1 Marker
300
1200
LoZ
48v
70 mm
Pin 1 Marker
EQ In
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Caution HOT!
O/P Phase
Caution - HOT!
Components
may become
hot during use
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Output Link
Option
Hot
Cold
HF
Gain
MF
Gain
MF
Freq
LF
Gain
Mic/Line
VTB9050
VTB9044
Opamp B
Opamp A
LF
Freq
Line Output
Separate PCB into individual sub-boards and fit headers
Long pin goes through PCB
Cut off excess pin and solder
Trim these 3 pins
very short so as not
to clash with C13
300
1200
LoZ
Mic/Line
48v
Caution HOT!
EQ In
Trim these pins very short so as not
O/P Phase
to clash with R2, R3 and R4
Fit sub-boards to main board
These 2 are identical
but should be fitted in
the order shown so that
the component numbers
agree with the schematic
PL8 PL9
300
1200
LoZ
48v
Mic/Line
EQ In
O/P Phase
Caution HOT!
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
HF
Gain
MF
Gain
MF
Freq
LF
Gain
LF
Freq
VTB9050
VTB9044
Caution - HOT!
Components
may become
hot during use
Output Link
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Opamp B
Opamp A
Option
Hot
Cold
Line Output
Input Transformer Assembly and Fitting
T1 = VTB9045 (1)
T2 = VTB9046 (1)
M3 Nylon Washers
(between transformer and PCB)
6BA x ¼ inch screws
Mic Gain
Line Gain
HPF
Freq
Make sure you put them the correct way round
Pin 6 in this position
for VTB9045
(mic input transformer)
VTB9045
Mic Input
Stage 1
Stage 2
VTB9043
Brown
Violet
Green
Orange
Black
Yellow
Red
Blue
Pin 6 in this position
for VTB9046
(line input transformer)
VTB9046
Line Input
Stage 3
VTB1847
CUTOUT
Output Link Option
Caution
HOT!
Hot
Cold
Scn
HF
Gain
MF
Gain
MF
Freq
LF
Gain
LF
Freq
VTB9050
VTB9044
Caution - HOT!
Components
may become
hot during use
Output Link
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Opamp B
Opamp A
Option
Hot
Cold
Line Output
Output Transformer Assembly and Fitting
60mm
10mm stripped ends
M3 Nyloc nut
M3 x 4mm unthreaded spacer
M3 x 35mm screw
Mic Gain
Line Gain
HPF
Freq
Stage 1
VTB9045
Stage 2
Brown
Violet
Red
Green
Blue
Orange
Black
VTB9043
Yellow
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
HF
Gain
MF
Gain
MF
Freq
LF
Gain
LF
Freq
VTB9050
VTB9044
Caution - HOT!
Components
may become
hot during use
Output Link
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Opamp B
Opamp A
Option
Hot
Cold
Line Output
PCB Assembly
M3 Plain Nut
M3 Shakeproof Washer
5 spacers required (only 2 shown for clarity)
2 x M3 Plain Washers
M3 x 35mm spacer
“EQ” PCB
Main “amplifier/transformer” PCB
M3 x 6mm “Sems” screw
Rotary Switch Adjustment Pins
Fit pins in positions shown then apply the self adhesive
silver washers over the pin holes to stop the pins coming out.
MF Freq
pins at
“12 O’clock”
and
“7 O’clock”
LF Freq
pins at
“12 O’clock”
and
“5 O’clock”
Mic Gain
pin at
“12 O’clock”
Line Gain
pins at
“12 O’clock”
and
“11 O’clock”
LPF Freq
pins at
“12 O’clock”
and
“5 O’clock”
Fitting Faceplate
LED1 = 2mm Red LED (1)
300
1200
LoZ
48v
Mic/Line
EQ In
O/P Phase
Short Leg
Long Leg
Faceplate Assembly Sequence:
1] Drop LED into switch PCB (don’t solder yet)
2] Put nuts onto rotary switches and pots... All the way down but
do not tighten them against the shoulder
3] Put washers onto rotary switches and pots
4] Fit faceplate
5] Loosely fit ring nuts to stop faceplate falling off
6] Place a 2.5mm drill bit shank between the faceplate and PCB
near to the mic gain switch
7] Tighten the ring nut for the mic gain switchso it “grips” the
faceplate… Not too tight that you cannot remove the drill bit.
8] Do the same for the other 4 switches
9] “Unscrew” the nuts of the rotary switches so that they tighten
up against the rear of the faceplate
10] Tighten the rotary switch ring nuts fully
11] Repeat 9&10 for the 3 pots
12] Push the LED through its faceplate hole so it is flush and
solder it in place (cutting off excess legs).
13] Fit switch knobs (see test procedure for correct
allignment of HF, MF, LF gain pot knobs).
Ringnut
Swtch / pot nut
2.5mm gap between PCB and rear of faceplate
Swtch / pot washer
Faceplate
Optional link cable (to give parallel output on right hand male XLR)
[This is probably best fitted after the unit has been fully tested]
Output Signal Cable (1 required)
Screen not connected
at this end (cut off)
45 mm
Signal +ve (Hot)Signal +ve (Hot)
Signal -ve (Cold)Signal -ve (Cold)
Signal Gnd (Screen)
HF
Gain
MF
Gain
MF
Freq
VTB9050
VTB9044
Caution - HOT!
Components
may become
hot during use
Output Link
ez1073 - 500 (Rev 4)
Not for commercial use
Output Bias
Adjust
Opamp B
Option
Hot
Cold
LF
Gain
LF
Freq
Mic Gain
Line Gain
HPF
Freq
Stage 1
Opamp A
VTB9045
Stage 2
VTB9043
Mic Input
Brown
Violet
Green
Blue
Orange
Black
Yellow
Red
VTB9046
Line Input
VTB1847
CUTOUT
Stage 3
Output Link Option
Caution
HOT!
Hot
Cold
Scn
Line Output
+48v (Pin 15)
Mic Input Hi
Mic Input Lo
48v
Switch subcard
LoZ
VTB9045
V Ref Negative*
Gain Stage 1 (subcard)
V Stage 1 + 2
Gain Stage 1 Feedback
Gain Stage 1 Output
Increasing Gain
+10
+15
+20
+25
+30
+35
+40
+45
+50
+55
+60
+65
Gain Stage 1 Output
Gain Stage 1 Input
V Ref Negative*
Phase
Line Input Hi
Line Input Lo
VTB9046
V Ref Negative*
+20
+16
+12
+8
+4
0dB
-4
-8
-12
Increasing Gain
(Decreasing pad)
Gain Stage 2 Input
+10
+15
+20
Mic/Line
Switch subcard
+25
+30
Gain Stage 2 (subcard)
+35
+40
Increasing Gain
Output Hi
+10
+15
+20
+25
+30
+35
+40
+45
+50
+55
+60
+45
+50
+55
+60
+65
Increasing Gain
Gain Stage 2 Boost
V Stage 1 + 2
Gain Stages
PCB
"EQ"
PCB
EQ Send (to EQ input)
EQ Return (form EQ output)
EQ In
Output Stage (subcard)
Switch subcard
+65
Switch subcard
V Stage 3 +
Heatsink
Chass Gnd
Output Lo
* V Ref Negative is at -16volts
-16
-20
Title
Prodigy ez1073 - 500 (Gain Stage)
Number
Rev
ez1073 - 500 (Rev 4)
30th Mar 2011
V Ref Negative*
Date
File
Drawn by
Sheet
1 of 3
EQ Input (from EQ send)
HF Shelf Level
MF Level
"EQ"
PCB
Gain Stages
PCB
EQ Output (to EQ return)
LF Shelf Level
Opamp A
(detail below)
LF Shelf Freq
Opamp B
(detail below)
HPF Freq
V Ref Negative*
MF Freq
Opamp A Input
Opamp A
Opamp A Output
Opamp B Input
Opamp B
Opamp B Output
V + EQ Stage
V Ref Negative* - EQ Card
* V Ref Negative is at -16volts
Title
Prodigy ez1073 - 500 (EQ Stage)
Number
ez1073 - 500 (Rev 4)
30th Mar 2011
Date
File
Drawn by
Sheet
2 of 3
Rev
Gain Stage 1 Sub PCB Connections
V Stage 1 + 2
V Stage 1 + 2
V Stage 3
V Stage 3
Main PCB
Gain Stage 2 Sub PCB Connections
Main PCB
Gain Stage 3 Sub PCB Connections
Main PCB
V Ref Negative
V Ref Negative
Gain Stage 1 Input Sub 1 Input
Gain Stage 1 Feedback Sub 1 Feedback
Gain Stage 1 Boost Sub 1 Boost
Gain Stage 1 Output
V Ref Negative
V Ref Negative
Gain Stage 2 Input
Gain Stage 2 Feedback
Gain Stage 2 Boost
Gain Stage 2 Output
V Stage 1 + 2
V Stage 1 + 2
V Ref Negative
V Ref Negative
Gain Stage 3 Input
Gain Stage 3 Base Drive
Gain Stage 3 Boost
Gain Stage 3 Output
Sub PCB
Sub 1 V Ref Negative
Sub 1 V Ref Negative
Sub 1 Output
Sub 1 +24v
Sub 1 +24v
Sub PCB
Sub 2 V Ref Negative
Sub 2 V Ref Negative
Sub 2 Input
Sub 2 Feedback
Sub 2 Boost
Sub 2 Output
Sub 2 +24v
Sub 2 +24v
Sub PCB
Sub 3 V Ref Negative
Sub 3 V Ref Negative
Sub 3 Input
Sub 3 Base Drive
Sub 3 Boost
Sub 3 Output
Sub 3 +24v
Sub 3 +24v
Boost Select
+48v Pin15
Main In Cold
Main In Hot
Primary 2 +
Primary 1 -
Mic Switch Common
Line Switch Common
Gain Stage 2 Input
Gain Stage 2 Boost
Gain Stage 2 Output
+16v pin 12
+16v pin 12
+16v pin 12
Line Input TX Hot
Upper Switch Sub PCB Connections
Main PCB
-16v pin 14
-16v pin 14
-16v pin 14
Sub PCB
Switch Sub: Boost Select
Switch Sub: +48v Pin15
Switch Sub: Main In Cold
Switch Sub: Main In Hot
Switch Sub: Primary 2 +
Switch Sub: Primary 1 Switch Sub: Mic Switch Common
Switch Sub: Line Switch Common
Switch Sub: Gain Stage 2 Input
Switch Sub: Gain Stage 2 Boost
Ribbon Cable Link between Gain Stages PCB and EQ PCB
V Ref Negative
HP Filter Feed
Vregulatedpos
Vregulatedpos
Vregulatedpos
V Ref Negative
Line Input TX Cold
V Ref Negative
V Ref Negative
Output Tx Cold
Main Out Hot
Output Tx Hot
Main Out Cold
EQ Output Feed
Gain Stage 3 Input
EQ Input Feed
Power LED
EQ Input Feed
-16v pin 14 - EQ Card
-16v pin 14 - EQ Card
-16v pin 14 - EQ Card
+16v pin 12 - EQ card
+16v pin 12 - EQ card
+16v pin 12 - EQ card
Line Input Hot
Lower Switch Sub PCB Connections
Main PCB
Sub PCB
Switch Sub: V Ref Negative
Switch Sub: Output Tx Cold
Switch Sub: Main Out Hot
Switch Sub: Output Tx Hot
Switch Sub: Main Out Cold
Switch Sub: EQ Output Feed
Switch Sub: Gain Stage 3 Input
Switch Sub: EQ Input Feed
Switch Sub: Power LED
V Ref Negative - EQ Card
Opamp B Output
Vregulatedpos - EQ Card
Vregulatedpos - EQ Card
Vregulatedpos - EQ Card
V Ref Negative - EQ Card
Line Input Cold
V Ref Negative - EQ Card
+48v DC; Pin 15
Output Link Option (screened wire link)
Chassis Ground;
Output HI;
Output LO;
Analogue Ground;
Input LO;
Input HI;
+16v DC;
PSU Common;
-16v DC;
Output HI;
Pin 2
Output LO;
Pin 4
Line Input LO;
Line Input HI;
+16v DC;
-16v DC;
Pin 1
Pin 2
Pin 4
Pin 5
Pin 8
Pin 10
Pin 12
Pin 13
Pin 14
Pin 8
Pin 10
Pin 12
Pin 14
Mic/Line Card
EQ Card
API References
API References
Voltage Conversion/Filtering/Distribution/Protection
+16v DC
Pin 12
Analogue Ground
Pin 5
PSU Common
Pin 13
Chassis Ground
Pin 1
-16v DC
Pin 14
AGnd
Vregulatedpos
+24v DC (relative to Vref Negative)
V Stage 3 +
V Ref Negative*
EQ Card Power
Vregulatedpos - EQ Card
V Stage 1 + 2
V + EQ Stage
Front Panel Power Led Indication
+16v DC; Pin 12
+48v DC; Pin 15
V Ref Negative
PSU Common
Pin 13
Power Led
Switch Sub Power Led
Switch Sub Ground
* V Ref Negative is at -16volts
V Ref Negative - EQ Card
Title
Prodigy ez1073 - 500(PSU)
Number
ez1073 - 500 (Rev 4)
Date
30th Mar 2011
File
Drawn by
Sheet
Rev
3 of 3
Caution HOT!
Caution - HOT!
Components
may become
hot during use
Output Link
Option
Hot
Output Bias
Adjust
Cold
HOT!
Caution
Hot
Cold
Stage 3
Scn
Output Link Option
CUTOUT
O/P Phase
EQ In
48v
Mic/Line
LoZ
1200
300
ez1073 - 500 (Rev 4)
VTB9050
Not for commercial use
Opamp B
VTB9044
Opamp A
Line Input
VTB9046
Mic Input
VTB9045
Stage 2
Stage 1
VTB1847
Brown
Violet
Red
Green
Blue
Orange
Black
Line Output
Yellow
VTB9043
HF
Gain
MF
Gain
MF
Freq
LF
Gain
LF
Freq
HPF
Freq
Mic Gain
Line Gain
Test Procedure
Much of this is unnecessarily pedantic....
You can just fit the EQ gain knobs “by eye”.... And simply set the “Bias Current” adjustment trimmer to draw a supply current of 110mA per rail
(or by measuring the voltage across the 1 Ohm resistor R49 [110mV])
1] Ideally power up the module on a jig from a current limiting bench power supply (+/- 16v) and check that the current settles to about 70mA per rail
2] Trim “Bias Current” adjustment trimmer to increase the current from 70mA to about 110mA (will be adjusted accurately later).
This can be done either by direct measurement of the current taken from the bench power supply or by measuring the voltage across the 1 Ohm resistor R49
3] Fit unit into lunchbox (with space to its right hand side as you will re-adjust the bias trimmer later)
4] Put a 0dBu 1000Hz signal into the line input (right hand XLR of its lunchbox slots) and measure the output (left hand XLR of its lunchbox slots)
5] Select “line” (mic/line switch), EQ out, 48v off, +phase.
6] Check that output changes from -20dBu to +20 dBu as line gain switch is turned through its range (4dB steps) ..... Set it to 0dBu (centre).
7] Change signal input frequency to 3000hz.
8] Switch EQ in, set HPF, LF, MF to “off”.... You should get 3000hz output at about -8dBu if HF put is fully counterclockwise.
9] Adjust HF pot (turn the shaft) until output is 0dBu..... Then fit the knob on its shaft with the pointer at the “0” position....
10] Change signal input frequency to 3200hz.
11] Adjust MF frequency switch to 3.2k......You should get 3200hz output at about -18dBu if MF put is fully counterclockwise.
12] Adjust MF pot (turn the shaft) until output is 0dBu..... Then fit the knob on its shaft with the pointer at the “0” position....
13] Adjust MF frequency switch back to “off”
14] Change signal input frequency to 110hz.
15] Adjust LF frequency switch to 110Hz......You should get 110hz output at about -18dBu if LF put is fully counterclockwise.
16] Adjust LF pot (turn the shaft) until output is 0dBu..... Then fit the knob on its shaft with the pointer at the “0” position....
17] Switch the EQ to “Out”
18] Change signal input frequency to 20hz.
19] Measure the THD+N (probably about 0.5%) .... Adjust the “Bias Current” adjustment trimmer clockwise until the distortion begins to increase
20] Adjust the “Bias Current” adjustment trimmer back (counter clockwise) one full turn.
21] Put a -10dBu 1000Hz signal into the mic input (left hand XLR of its lunchbox slots) and measure the output (left hand XLR of its lunchbox slots)
22] Select “mic” (mic/line switch), EQ out, 48v off, +phase..... Mic gain switch fully counter-clockwise
23] Check the output measures 0dBu
24] Decrease the signal input level by 5dBu and turn the mic gain switch one “click” clockwise
25] Check the output measures 0dBu
26] Repeat for all mic gain switch positions.
27] Toggle the 300/1200 switch to the 300 position, the output should increase to approx. +3.5dBu
28] Toggle the phase switch to the “-” phase position.... The output phase should invert.
29] Disconnect the input XLR
30] Toggle the 48v switch to the “on” position
31] Measure the voltage between pin 2 and pin 1 of the XLR input (it should be 48v)
32] Measure the voltage between pin 3 and pin 1 of the XLR input (it should be 48v)
32] Toggle the 48v switch to the “off” position... The voltage on pin2&3should decay to zero.
33] Put a 0dBu 1000Hz signal into the line input (right hand XLR of its lunchbox slots) and measure the output (left hand XLR of its lunchbox slots)
34] Select “line” (mic/line switch), EQ in, 48v off, +phase.
35] Plot the frequency response for all EQ frequency ranges and gain min/max settings and check against graphs.
2
2
Hz
Hz
5
+15
+20
+
+10
+5
+0
-5
-10
-15
-20
20 20k50 100 200 500 1k 2k 5k 10k
-25
5
+15
+20
+
+10
+5
+0
-5
-10
-15
-20
-25
20 20k50 100 200 500 1k 2k 5k 10k
+25
+20
+15
+10
+5
+0
-5
-10
-15
-20
-25
20 20k50 100 200 500 1k 2k 5k 10k
+5
+0
-5
-10
-15
-20
-25
-30
-35
-40
-45
20 20k50 100 200 500 1k 2k 5k 10k
-50
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