Music-On-Hold Interface – MOH-379

MOH-379 Music-On-Hold Interface

The MOH-379 Music-On-Hold Interface provides gain and isolation for connecting an external audio source to the music on hold input of a telephone system. It converts an unbalanced stereo pair to both a mono balanced output and a mono unbalanced output each with separately adjustable gain. The balanced output is transformer isolated, and it’s bandwidth is limited for better compatibility with telephone systems. Conventional dual input connectors provide both RCA and screw terminals. The MOH-379 is built into a rugged dicast aluminium box. Power is supplied via 24 VDC CSA/UL approved adapter.

MOH-379 Music-On-Hold Interface Cover


Input Connections:
RCA or screw terminal

Frequency response:
(@+4dB output into 600ohms)
200Hz – 10kHz balanced (bandwidth limited)
35Hz – 40kHz unbalanced

Maximum Output:
+16dBm balanced
+20dBm unbalanced

Maximum gain:

Residual noise:
-80dBu at full gain, balanced
-80dBu at full gain, unbalanced


4.5″L x 2.4″W x 1.25″D

Power supply:
24 VDC CSA/UL approved adapter (included) or ±12 VDC to ±17 VDC bipolar supply

Click here for wiring diagram