ARX MSX 12 - 4 in, 12 Out ISO-Transformer MicrophoneLine Splitter

About the MSX 12

The ARX MSX 12 Transformer isolated Microphone/Line Splitter has been developed to deliver noise-free audio splitting with minimal setup time. Its intuitive layout and clear, uncluttered labelling enables a quick and easy solution to the increasing complexity of today’s standards of audio production.

The MSX 12 is a totally passive device requiring no power, and consists of Four channels of transformer isolated ultra low noise Microphone/Line Splitter. Each of these channels has a direct looped Main/FOH feed, and a transformer isolated Monitor split on the front panel.

On the rear panel is an Auxiliary transformer isolated split ideal for use with a remote recording truck or TV feed.

Marker panels on the front provide a space where individual channel connections can be noted.

The all-steel chassis of the MSX 12 provides strong interference resistant shielding. Internally, state-of-the-art transformers deliver superb audio quality and total galvanic isolation.

The MSX 12 is the easy answer to multi channel signal splitting requirements.

Front Panel detail, showing Input and hard-wired Main output,
plus transformer isolated Monitor output

Typical System Layout using the MSX12

Every MSX12 is hand soldered, with a 48 hour burn in followed by a 100% re-test and visual PCB QC check prior to shipping. Which is why we say...

Input Impedance 300 Ohms

Output Impedance 2 secondaries @ 600 Ohms each

Frequency Response 30Hz - 20 KHz ± 1dB

Maximum Output Level + 20dBm

THD at Max Output 0.2% 30 Hz - 20KHz @ 20dBm

Insertion Loss 0.5dB @ 1 KHz (600 Ohm source & load)

Input Connectors 3 pin female XLR wired Pin 2 + Hot, Pin 3 – Cold

Main Output 3 Pin male XLR wired Pin 2 + Hot, Pin 3 – Cold

Monitor & Aux Output Split 3 pin male XLR wired Pin 2 + Hot, Pin 3 – Cold. Audio grounds not connected; Pin 1 is floating.

Weight 5 lbs (2.2 Kg)


Rear Panel detail, showing transformer isolated Split output
and Chassis Ground point

Front Panel

  • 4 x Hardwired balanced XLR Input and Main Outputs. Pin 3–, Pin 2 +, Pin 1 Ground
  • 4 x Hardwired transformer isolated balanced XLR Monitor Splits. Pin 3–, Pin 2 +, Pin 1 floating (not connected)
  • Marker panel for labelling individual channel assigns


Rear Panel

  • 4 x Hardwired transformer isolated balanced XLR Auxiliary Splits. Pin 3–, Pin 2 +, Pin 1 floating (not connected)
  • 2 x D Sub connectors for Monitor Splits
  • 2 x D Sub connectors for Auxiliary Splits
  • Screw Terminal Chassis Ground point

Note: No connections to Audio ground