Henry Engineering STEREOMIXER User manual

STEREOMIXER
EIGHT INPUT STEREO MIXER
HENRY ENGINEERING
503 Key Vista Drive
Sierra Madre, CA 91024
tel: [phone]
fax: [phone]
website: www.henryeng.com
DESCRIPTION
STEREOMIXER is an eight-input, two-output stereo line level mixer/combiner for utility use. The
unit has balanced bridging inputs for eight audio sources (4 stereo pairs or 8 mono sources)
which can be mixed to two outputs in stereo or to one output in mono. A level control is
provided for each input. The output DC coupled circuitry provides excellent sonic performance.
INSTALLATION
All connections to the StereoMixer are made via plug-in connectors. Remove about 1/8” of
insulation, insert wires into the plug, and tighten the screws. Be sure that no bare wires are
exposed.
Audio inputs to the StereoMixer should be connected to the balanced input terminals labeled 1
thru 8. For unbalanced inputs, install a jumper between the (-) terminal and G (ground). All
inputs are bridging; it is not necessary to terminate the source unless required by the source
equipment.
Audio outputs from the StereoMixer are connected to the two outputs labeled L (Left) and
(Right). The output circuitry will drive any load of 600 ohms or higher. It is not necessary to
terminate the outputs. For unbalanced outputs, connect to the (+) and G terminals only. DO
NOT short the (-) terminal to ground.
OPERATION
The input levels to the StereoMixer should be between -10 and +8 dBm. Adjust each input
channel using the INPUT LEVEL controls. Unity gain is achieved with these controls set to 10
o'clock; with nominal input levels of +4 dBm the Input Level controls should be run near this
setting. It is recommended that input levels be initially set with a level indicator (VU meter,
scope, VOM) temporarily connected to the StereoMixer's output to monitor output levels. The
average output level should not exceed +8 dBm to ensure adequate headroom.
StereoMixer can operate in either stereo or mono, determined by the OUTPUT MODE switch.
In Stereo mode, the odd numbered inputs are mixed to the Left output; the even numbered
outputs are mixed to the Right output. In Mono mode, ALL inputs are mixed to the Left output.
(The right output is not used in mono mode.)
SPECIFICATIONS
INPUTS -10 to +8 dBm; balanced 20K or unbalanced 10K
GAIN 10 dB maximum
OUTPUTS +4 dBm nominal, +26 dBm max; 600 ohms or higher, 4X
FREQ RESP DC to 20 kHz, +/- 0.25 Db
NOISE 80 dB below +4 dBm output
CROSSTALK 75 dB below +4 dBm output, typ. @ 1 kHz
DISTORTION .008% IM/THD

5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
GROUND TIE
1R
1. ALL RESISTORS ARE 1/4W, 1%.
INPUTS
LEFT
1L
NOTE: UNLESS OTHERWISE SPECIFIED
RIGHT
++
-
-
-
-
B
OUTPUTS
+
+
+
3R
+
-
-
3L
+
4L
-
+
4R
-
+
+
-
2R -
2L
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
BIPOLAR POWER SUPPLY
WHT
PRI
AC
SEC
115V
230V
AC BLK
3600 A
SCHEMATIC: STEREOMIXER
HENRY ENGINEERING
503 Key Vista Drive
Sierra Madre, CA 91024 USA
telephone - [phone]
FAX [phone]
11Friday, February 21, 2003
Title
Size Document Number Rev
Date: Sheet of
-15V
-15V
-15V
-15V
+15V
+15V
-15V
+15V
+15V
-15V
-15V
+15V
+15V
-15V
-15V
+15V
-15V
+15V +15V
+15V
-15V
-15V
+15V
+15V
+15V
-15V
+
-
U2A
NE5532
3
21
8 4
R1 24.9K
C16
.001uF
R17
5K VAR
1 3
2
C24
.1uF
+
C19
330uF 25V
C21
.1uF
+
-
U5B
NE5532
5
67
8 4
C13
.001uF RP5E
6.34K DIP
512
C3
.001uF
R4 47, 5%
E8
R13
5K VAR
1 3
2
E1
Q2 LM7915
2 3
1
IN OUT
GND
RP3H
10K DIP
8 9
R8
5K VAR
1 3
2
D3
1N4004
C11
.001uF
R6 10K
+
-
U3B
NE5532
5
67
8 4
+
C20
330uF 25V
R10 47, 5%
TP3
1
RP4A
6.34K DIP
116
RP5B
6.34K DIP
215
TP2
1
C23
.1uF
RP3E
10K DIP
512
+
-
U6A
NE5532
3
21
8 4
SW1
2
1 3
C1
.001uF
E9
RP4C
6.34K DIP
314
C12
.001uF
E2
RP3C
10K DIP
314
LED1
LED
R3
5K VAR
1 3
2
C9
.001uF
R15 10K
J1
1
2
3
4
5
6
R12
5K VAR
1 3
2
R11 24.9K
RP1E10K DIP
512
J2
1
2
3
4
5
6
RP1C10K DIP
314
RP4E
6.34K DIP
512
RP4F
6.34K DIP
611
J3
1
2
3
4
5
6
C2
.001uF
TP1
1
R5
24.9K
RP4G
6.34K DIP
710
C15
.001uF
RP5A
6.34K DIP
116
RP5D
6.34K DIP
413
J5
1
2
3
4
5
6
C10
.001uF
RP3G
10K DIP
710
RP1G10K DIP
710
E4
C5
.001uF
RP1B10K DIP
215
RP1A10K DIP
116
+
-
U1B
NE5532
5
67
8 4
RP4H
6.34K DIP
89
C22
.1uF
C7
.001uF
+
-
U1A
NE5532
3
21
8 4
R2
5K VAR
1 3
2
+
-
U2B
NE5532
5
67
8 4
C14
.001uF
RP2C10K DIP
314
+
-
U6B
NE5532
5
67
8 4
C4
.001uF
C17 30pF
RP2E10K DIP
512
RP1F10K DIP
611
R9
5K VAR
1 3
2
E5
RP1D10K DIP
413
RP4D
6.34K DIP
413
R14 47, 5%
C6
.001uF
RP5C
6.34K DIP
314
RP2G10K DIP
710
D2
1N4004
RP2A10K DIP
116
RP4B
6.34K DIP
215
RP3D
10K DIP
413
J4
1
2
3
4
5
6
RP1H10K DIP
89
E6
RP5H
6.34K DIP
89
F1
115V: 250 ma; 230V: 125ma
C18 30pF
T1
SPW-061
1
3
4
2
5
6
8
7
R18
5K VAR
1 3
2
RP5F
6.34K DIP
611
R7 10K
RP2D10K DIP
413
+
-
U3A
NE5532
3
21
8 4
RP2F10K DIP
611
D4
1N4004
RP5G
6.34K DIP
710
RP3F
10K DIP
611
R20
3.9K, 5%
C8
.001uF
+
-
U4A
NE5532
3
21
8 4
Q1 LM7815
3
2
1
IN
GND
OUT
RP3B
10K DIP
215
RP3A
10K DIP
116
R19 47, 5%
R16 10K
RP2H10K DIP
8 9
E7 D1
1N4004
+
-
U5A
NE5532
3
21
8 4
RP2B10K DIP
215
+
-
U4B
NE5532
5
67
8 4