STEREOMIXER
EIGHT INPUT STEREO MIXER
HENRY ENGINEERING
503 Key Vista Drive
Sierra Madre, CA 91024
tel: 626.355.3656
fax: 626.355.0077
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 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
