
Microphone Mixer/Preamplifier
Model #555-4945
This device is warranted from defects for one year from the date of purchase. Should it require
service, either within or beyond that warranty period, please contact your MCM Sales
Representative.
This unit includes a host of features, along with an impressive list of specifications, which are
detailed over the next pages. Please take the time to read this document completely prior to
installation of this product. Should you have questions regarding installation or operation of this
unit, please contact the MCM Technical Support Department.
MCM Custom Audio products are warranted, by MCM Electronics, against manufacturer defects for a
period of one year from the original date of purchase. This warranty is limited to manufacturer
defects, in either materials or workmanship. MCM Electronics, or any other worldwide divisions of
Premier Farnell PLC, are not responsible for any consequential or inconsequential damage to any
other component, structure or the cost of installation or removal of said items.
650 Congress Park Drive
Centerville, Ohio 45459
www.mcmelectronics.com
© 2009 MCM, a Premier Farnell Company
MCM Electronics

Congratulations on your purchase of this
MCM Custom Audio Microphone Mixer / Preamplifier
This device was designed specifically to allow the audio from up to two microphones to be inserted
onto the A/V signal path from any DVD, VCR or similar video player. While passing the composite
video signal through unchanged, two microphones are added to the audio signal, allowing this to be
used in video presentations, narrations, or simple karaoke applications. For added effect, adjustable
echo may also be added to the microphones audio.
Additionally, by disregarding the video feed through connections, this device may be used as a
stand alone microphone preamplifier or simple mixer, combining a stereo line level source, with two
mic level inputs.
Connections / Controls
1. L/R Line Level Input – Accepts stereo
line level audio signal from CD and DVD
players, VCR's or any other audio source.
2. Composite Video Input – Provides video
feed through signal to the Composite Video
Output. This signal is not affected by this
device, these connections are provided
merely for convenience.
3. L/R Line Level Output – Provides mixed
audio output signal to standard stereo
amplifiers, or audio input on televisions or
video monitors. The signal level and stereo
integrity from the audio input is
maintained, while each microphone input is
evenly applied to both channels.
Specifications
x Audio Sensitivity: 300mV line level,
10mV mic level
x Audio Output: 300mV
x Frequency Response: 20Hz ~ 20KHz
(line level)
x Frequency Response: 50Hz ~ 20KHz
(mic level)
x Total Harmonic Distortion (THD): 0.02%
x Power requirements: 24VDC
x Dimensions: 1.75" (H) x 5.5" (W) x 4"
(D)
4. Composite Video Output – Provides
video feed through signal from the
Composite Video Input.
5. DC Power Input – Accepts 24VDC supply
voltage from the included AC adaptor.
6. Microphone Inputs – Female 1/4" jack
accepts mic level signal from standard
dynamic microphones.
7. Mic Level Controls – Adjusts the mic level
for each corresponding input, as it is mixed
onto the existing audio track.
8. Echo – This control adds echo effect to the
microphone inputs. Rotating the control
clockwise increases the amount of depth
and delay of the echo. Full
counterclockwise rotation of this control will
provide "straight" playback, with no echo
effect.
9. Power Indicator – Indicates power is
applied to the unit through the provided AC
adaptor. Since there is no ON/OFF selector
provided, and current draw from this device
is very low, it is completely acceptable to
leave this device powered continuously.