Valcom VMT-1 Product Manual

CONNECTIONS
The VMT-1 provides an impedance match
between a 500-600 Ohm balanced line and a
high impedance auxiliary or microphone input of
an amplifier.
The VMT-1 may also be used to attenuate the
audio output of a 25-volt amplifier to a level
suitable to connect to a line level input.
Connections to the HI Z I/O of the VMT-1 may
be made via standard phono patch cable or via
screw terminals.
Connections to the 600-Ohm I/O of the VMT-1
may be made via screw terminals.
DIMENSIONS/WEIGHT
•
1.75" H x 3.75" W x 1.25" D
(4.45cm H x 9.53cm W x 3.2cm D)
•
0.5 lbs. (.23 kg)
Figure 1: Shows the VMT-1 being used to
connect a 600-Ohm balanced line output to the
auxiliary input of a commercial amplifier. If the
amplifier uses phono jacks for auxiliary input
connections a patch cable with male phono ends
may be used for the connection. Shielded single
conductor wiring should be used when the
amplifier is equipped with screw terminal
connections.
HI Z
HI Z
600-OHM
SHLD CT
Phono
OR
Plug
600-OHM Balanced Line
FIGURE 1: Input Matching Transformer
VMT-1
INPUT MATCHING TRANSFORMER
Shorting
Jumper in
Normal
Position
M
I
C N
O
R
M
Shield
Phono
To Aux. Input
Plug
of Amplifier
1
Figure 2: To connect a 600-Ohm line output to a
1/4" microphone input of an amplifier, move the
shorting jumper to the upper 2 header pins
on the unit.
HI Z
600-OHM
HI Z
CT
SHLD
Phono
OR
Plug
600-OHM Balanced Line
FIGURE 2: Connection to Microphone Input
Issue 2
Shorting
Jumper
In Mic.
Position
M
I
C N
O
R
M
Shield
To Mic. Input
Phono
of Amplifier
Plug
Female Phono to ¼" Male
Switchcraft 343 or Equiv.
947993