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MS3      Microphone Splitter



  • Provides 3-way Split for Low Impedance Microphone
  • 1 Direct and 2 isolated Outputs
  • Great for Musicians' Monitoring and Recording
  • Uses Include Press Conferences and Speeches
  • Connects with Standard Microphone Cables
  • High Quality Transformer-Isolated Output
  • Rugged ProCo Uni-Box Construction Provides Protection and EMI/RFI Shielding



The ProCo TradeTools MS3 Mic Splitter splits a signal from a low impedance microphone (or similar source) into three outputs, enabling three microphone preampliers to be fed from one source.  Some applications include musicians' on-stage monitoring, live recording, ENG use at press conferences, and videotaping of lectures, public speeches, etc.  It can also be used simply as an isolation transformer for long microphone lines feeding unbalanced inputs, or for any audio signal up to 0 dBv (.775 volt). Transformer isolation in such situations minimized interference from EMI/RFI and ground loops.  The transformer-isolated feeds retain the advantage of common-mode noise rejection inherent in the use of balanced lines.

The MS3 is fitted with standard 3-pin XLR-type connectors for INPUT, DIRECT OUTPUT, and ISO OUTPUTS 1 and 2, so hookup requires only standard microphone cables.  The use of the ProCo MBT-2 transformer allows the MS3 to provide two floating, low impedance outputs with wide, flat frequency response, ultra-low distortion, and minimal ringing or overshoot to degrade transient response.  The transformer's triple electrostatic shields and GND/LIFT switches provide isolation and buzz-free operation in virtually any environment.

The MS3's ruggedly constructed "Uni-Box" enclosure is formed of extruded aluminum side channels and 16-gauge steel top, bottom and end plates, and is designed to protect switches and connectors from accidental damage.  The use of steel also provides excellent magnetic shielding for the transformer from 60 Hz AC hum fields.  Top quality connectors and switches provide trouble-free service even in abusive situations such as remote recording and broadcast operations.


All measurements made with 150Ω source feeding INPUT and 1.0 kΩ loads on all ISOLATED OUTPUTS to simulate typical "real world" microphone and mic preamps. 0 dBv ref. = .775 volts.
NOTE: Phantom power (if required) must be supplied by mixer (or suitable power supply) connected to DIRECT OUTPUT.

Frequency Repsonse:

20 Hz - 20 kHz, ± .25% @ -15 dBv output.
-3 dB @ approximately 140 kHz.

Total Harmonic Distortion:
<.03% 20 Hz - 20 kHz @ -30 dBv output.
<.1% 30 Hz - 20 kHz @ -15 dBv output.
<.25% 20 Hz - 20 kHz @ -15 dBv output.
Phase Response:
<-13 degrees @ 20 kHz (ref. 1.0 kHz).

Rise Time:
<2.4 microseconds (2.0 kHz square wave, 10%-90%).

Voltage Loss:

<2.5 dB @ 1.0 kHz.

Input Impedance:
>570 Ω @ 1.0 kHz.
>570 Ω @ 10kHz.
Nominal source impedance is 150 Ω.

Output Impedance:
<255 Ω @ 1.0 KHZ.
<270 Ω @ 10 kHz.
Nominal output impedance is 1.0 kΩ.

Maximum Input Level for 1% THD:
0 dBv @ 20 Hz.
+4 dBv @ 30 Hz.
+8 dBv @ 50 Hz.