Samson MD1 DI Box passive mono

The specialist's opinion

The Samson MD1 is a passive mono DI box designed by Samson Technologies, an American brand active in the field of professional audio since 1980.

Compact, robust and economical, it offers a simple, reliable solution for connecting an instrument to a preamplifier, mixing console or audio interface, without requiring phantom power or batteries.

Unbalanced to balanced conversion with STL transformer

The MD1's main role is to convert the unbalanced instrument-level signal from a guitar, bass, keyboard or drum machine into a balanced microphone-level signal compatible with the XLR inputs of consoles and audio interfaces. This conversion is handled by Samson's custom STL transformer, which covers the entire audible range and beyond - from 18 Hz to 40 kHz with a flat frequency response to ±0.1 dB - while eliminating hum and RF interference thanks to its shielding. The galvanic isolation provided by the passive transformer also protects against ground loops responsible for the parasitic hum so common when connecting instruments in sound systems.

Symmetrical XLR output and Thru jack for stage Amplifier

The MD1 features a Thru input and output in unbalanced 6.35 mm jack format, enabling the instrument signal to be fed back to a stage amplifier or monitor without affecting the quality of the signal sent to the console. The balanced XLR output provides a clean signal that's less sensitive to noise than unbalanced cable, allowing cable runs over long distances without noticeable degradation. A ground lift switch disconnects pin 1 of the XLR output to eliminate ground loops and persistent hum. Input impedance is 400 kΩ and output impedance is 250 Ω.

14-gauge steel chassis and Bar performance

The 14-gauge steel chassis offers proven robustness for intensive stage use, protecting internal connections, welds and components from shock and vibration. Dynamic range exceeds 100 dB at balanced output, noise floor is -117 dB and total harmonic distortion remains below 0.03% from 20 Hz to 40 kHz. The maximum input level supported is 20 dBu. No external power supply is required.